Safe to Drive with P0420 code? Long story short, I had a milltek turboback system with 100 cell cat fitted on Friday and I was out and about today and pulled out of a corner in 3rd, changed down to 2nd and put my foot down. As soon as I did that the CEL light and traction control light came on with the cruise control light on, still ran fine ect.Back story: I picked up my '10 (NA) Forester (200k miles) two years ago for a song and a dance (mostly because BIL wanted something newer). It needed a new catalytic converter, so I bought the cheapest one on Amazon, and everything was good. The issue: Two months ago, I got CEL for a catalytic converter below threshold (P0420).Sub2013 Discussion starter. 6 posts · Joined 2021. #1 · Sep 27, 2021. I recently purchased used 2013 Forester and the 2nd day received the dreaded code p0420. This code drives me crazy! This also stops AWD From working and the cruise control.. I would love to know or be able to use my AWD.The P0420 CEL code + reduced gas mileage would point me upstream. The rear O2 sensor is good, as it's telling you there too much O2 in the exhaust... as in, you're running too rich. So rich that the CAT can't reduce the O2 levels. That would also explain the poor gas mileage.Well I can add my Forester to the P0420 club. I do not think I have a cat problem fuel economy is fine, no foul odors or noxious fumes when car is started in garage. ... Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Full Forum Listing. Explore Our Forums.VSurfn. 1329 posts · Joined 2014. #2 · Jul 22, 2018 (Edited) P0420 code stands for “Catalyst System Efficiency Below Threshold (Bank 1).”. When you receive a P0420 code it means your catalytic converter is not operating at maximum efficiency. Usually this means your catalytic converter needs to be replaced and/or your O2 (oxygen) sensors.When I started up my Forester (2017 2.5i Premium) this morning the car beeped and I saw two messages on the console (if that's what the window above the center of the dashboard is called). The first said: CHECK ENGINE: Emission control system needs to be checked".The P0420 set the CEL AND made the cruise contrl light blink. The Cel is obvious as to why it was on. The P0420 did that. Now the blinking cruise, On Subaru's with 'drive-by-wire' the cruise control is integrated into the ECU, but is a seperate co-processor. If it detects any engine faults that will cause it to malfuction, it will disable ...2010 Subaru Forester, with P0420 Code. Dealer states the Catalytic converter needs replaced. Question is whether the converter in the pretzel style exhaust line can be replaced without replacing the d … read moreI have 2007 forester with 49000 miles I am reading code P0420 anyone has had any issues with this. ... Newer Generations of Subaru discussion ; 1990 to Present Legacy, Impreza, Outback, Forester, Baja, WRX&WrxSTI, SVX ; P0420 P0420.P0420 is VERY RARELY a failing cat. It is most commonly a failing oxygen sensor (front Subaru, rear any brand), vacuum leak, exhaust leak or what not. Search that code on the forums and you'll find plenty of info. Cats rarely fail without serious mechanical problems, I think your mechanic wants to give you an expensive repair bill.idosubaru. 12342 posts · Joined 2009. #2 · Feb 19, 2013. most likely the 0420 code was there before and cleared before you bought it (or before your friend bought it at auction). it may even be one of the reasons it went to auction if the poor former owners got quoted a converter to fix it.MY06 Forester Shifting Problems, P0420. 5575 Views 10 Replies 4 Participants Last post by greenlakejohnny, Jan 31, 2013 Jump to LatestPO420 code. Thanks for taking the time to help. I have a 2004 Outback 2.5L automatic. J259. Code P0420. I've replaced the bank 1 sensor 1 with a Denzo brand. I've ran 2 different cleaners through the gas tank. I got the car with a blown head but had it fixed. I replaced the sensor after the head was fixed.The P0420 is a finicky code. There is a range of "acceptable" parameters that Subaru has set. If the O2 sensor sees a value that is outside of that range, even for just a fraction of a second, you get the P0420. Adding the extension doesn't stop the O2 sensor from working, it just doesn't get the immediate read, but more of a mixed read.P0507 Subaru Code - Idle Control System RPM Higher Than Expected. How to Fix. Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.Jul 16, 2007 · Forester 2001 L - Stock 101k Miles P0420 - Catalytic Converter Efficiency Below Threshold The forester has been throwing this code for a few months now, typically shows up on long highway runs (but to be fair, that is the vast majority of my driving). I bought a scanner from scantool.net, which I am quite impressed with for $60 new.I'm very new to these Forester hells having just gotten a 2010 and recently got the dreaded P0420 code. In Youtubes suggesting several possible solutions the catalytic converter cleaner added to 1/4 full fuel tank was the first suggestion. Do any of you have successful experience with that, or terrible experience with that like it ate gaskets ...My Forester (1999, 125,500 miles) started acting strange last night. On my way home, it felt like it was losing power, then felt like a cylinder or two were misfiring, then started sputtering and stalling. Luckily, I was able to make it home. Diagnostics told me that three of my four cylinders were misfiring, so I purchased plugs & wires ...Exhaust leaks are known to cause P0420 codes. OEM Cats are $1200 ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less . Full Forum Listing. Explore Our Forums.Master. 5,081 Answers. CODE P0420. P0420 - Catalytic Converter Efficiency Below Threshold. This is a catalyst inefficiency code, it is most likely caused by either a bad cat or modified (catless) exhaust. It is unlikely to be a bad 02 sensor. The readings from the rear 02 sensor are used to determine whether to set this code, but if the sensor ...My '06 X has infrequently given me the P0420 code, and when it does it keeps coming back for a short while. Well, ... We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less . Full Forum Listing.Here are some possible causes and solutions (including some things you've checked already): - The MAF (Mass Air Flow) Sensor is dirty or faulty. Easy clean method is remove the MAF, blast it inside and out with aerosol brake cleaner, re-install. Check the wire harness for damage, frayed wires, etc. - Use of "oiled" air filters may cause the MAF ...SERVICE INFORMATION BULLETIN. APPLICABILITY: 2017-19MY Legacy & Outback 2.5L 2020-23MY Legacy & Outback 2017-23MY Impreza & Crosstrek 2017-18MY Forester 2.5L 2019-23MY Forester 2018-23MY WRX 2019-21MY Ascent. SUBJECT: DTC P0420 Diagnostic Procedure. NUMBER: DATE: REVISED: 09-110-23R. 10/09/23 11/07/23. INTRODUCTION:Causes of the P0420 Code. Several issues can lead to the P0420 code in a Subaru Forester. Here are the most common causes: Failing Catalytic Converter: The most direct cause is a catalytic converter that is no longer effective. Oxygen Sensor Malfunction: Faulty oxygen sensors can send incorrect data, leading to a P0420 code.45844 posts · Joined 2007. #4 · Jul 22, 2014. Yes, fixing the P0420 CEL code could improve your gas mileage. The rear O2 sensor on the '03 monitors the exhaust flow for excess 02 & doesn't affect the operation of the engine as it does on the '05+. The P0420 CEL code could be caused by many things, but one is an over rich condition which ...Subaru Forester 2014 I have a cel with code p0420 on and off,CEL came up drove for 70KMS and it went off the moment I had filled in gas. It comes on and off. Should I take it to mechanic or keep drivingIm getting the p0420 in an 04 forester 2.5xt turbo. Ive narrowed it down to actually being a cat problem. My issue is trying to figure out which cat to buy. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.HƯỚNG DẪN SỬ DỤNG FORESTER: HỆ THỐNG NÚT BẤM TRÊN XE - Subaru Hà Nội. Dù nội thất Forester được thiết kế tinh tế và tối giản, nhưng nhiều khách hàng vẫn bỡ ngỡ khi lần đầu thao tác trên chiếc Subaru Forester.The P0420 code usually came back with 1 to 2 years in the reviews. I rolled the dice on a middle of the road unit, and fortunately it lasted at least 3 years, and may still be good, as I no longer own the car. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability ...The future of fully autonomous robots may be built by a company that is laser scanning the boreal forests of Finland with drones. Helsinki-based Sharper Shape is already bringing a...59 posts · Joined 2015. #1 · May 23, 2020. I'd greatly appreciate some help troubleshooting a P0420 code on my '07 OB. I've reviewed many posts on this, including the P0420 Diagnosis post on the Problems and Maintenance forum, but I'm not understanding some of the basics. Many of the posts refer to checking for exhaust leaks.The P2097 code indicates that the post-catalyst fuel trim system is too rich in bank 1. The Heated Oxygen Sensors (HO2S) are used to monitor the oxygen content of the exhaust stream. The Engine Control Module (ECM) uses the HO2S voltage to determine the air to fuel ratio. An HO2S voltage that increases above bias voltage toward 1 000 mV ...I'm very new to these Forester hells having just gotten a 2010 and recently got the dreaded P0420 code. In Youtubes suggesting several possible solutions the catalytic converter cleaner added to 1/4 full fuel tank was the first suggestion. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester ...Do a search for P0420 (should be code you have). There are significant quantity of problems w/ catalytic converters on late 90's early 2000 Foresters and replacing doesn't always work permanently. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the ...2006 Subaru Forester X, 2.5 non turbo, automatic, 288K miles. In the past, I started experiencing P0420 codes around 190K miles. After experimenting with different gas tank potions and solutions (even the popular $5 fix) and after replacing the A/F and downstream O2 sensor, I elected to replace the entire exhaust system.Jan 29, 2024 · The P0420 code is a common diagnostic trouble code that indicates an issue with the catalytic converter in a Subaru Forester. This code is significant as it can affect the vehicle’s emissions and overall performance. In detail: The P0420 code specifically points to a problem with the efficiency of the catalytic converter.2008 - O2 Sensor and P0420 Cat Code? ('06-'08) Jump to Latest Follow ... Subaru Forester Owners Forum. 2.6M posts 191.2K members Since 2006 We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. ...That has fixed the P0420 code for me multiple times on several different Subies. It's a small investment compared to replacing the entire cat. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.No matter the situation, Advance Auto Parts has the Oxygen Sensor product you desperately need. We currently carry 13 Oxygen Sensor products to choose from for your 2006 Subaru Forester, and our inventory prices range from as little as $77.99 up to $262.57. On top of low prices, Advance Auto Parts offers 4 different trusted brands of Oxygen ...The next Subaru is a 2006 Forester. This car was very tolerant of the same type of auto parts. I got this 2001 Outback last fall...if it had been my first Subaru, it would be my last. ... P0420 is a nag code with these, and sadly is not well defined or contained (I think a 2005 or newer subaru, one would get additional codes to trace it better).My '06 X has infrequently given me the P0420 code, and when it does it keeps coming back for a short while. Well, ... We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less . Full Forum Listing.Jul 30, 2017 · P0420 - Catalyst System Efficiency Below Threshold (Bank 1) P0031 - HO2S Heater Control Circuit Low (Bank 1 Sensor 1) P0134 - O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1) The last 2 CEL codes are pointing to a defective front O2 sensor or the wiring to the front O2 sensor. The most recent was replacing the front O2 sensor on the cat.P0420 Catalyst System Efficiency Below Threshold; P0171 System Too Lean; P014D Manufacturer Defined - O2 Sensor Slow Response - Lean to Rich (Bank 1 Sensor 1) ... Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less . Full Forum Listing.Forester 2001 L - Stock 101k Miles P0420 - Catalytic Converter Efficiency Below Threshold The forester has been throwing this code for a few months now, typically shows up on long highway runs (but to be fair, that is the vast majority of my driving). I bought a scanner from scantool.net, which I am quite impressed with for $60 new.If you're looking for a reliable and performance-oriented vehicle, the Subaru P0026 is an excellent choice. How to Diagnose and Repair a P0026 Subaru Code. Diagnosing and repairing a P0026 Subaru code can be daunting for a novice mechanic. However, with the right information and knowledge, it is possible to diagnose and address the issue.This turned out to be a bad ignition coil. Replaced it, and the car runs and drives great. After about 50-100 miles of driving, it threw the P0420 code. (with a bunch of other dash lights like I read the subarus do). seems to run fine. I have an OBD2 adapter and Torque pro, and I did a few readings. One screenshot is idle, one is around 2k RPMS.Our family has 3 Subarus. On our 2009 Impreza 2.5i I was getting the p0420 code. We drove it that way for several months not knowing if it was the Catalytic Converter or one of the o2 sensors. I called the local Subaru dealership and they said I would have to pay for a diagnostic and a replacement Catalytic Converter if that was the problem.2005 subaru forester w/ 320k. A few months back, my sputtering/shuttering problem threw the codes P0031, P0134. I replaced the upstream o2 sensor and it appeared to fix the issue. Now the sputtering at low RPMs is back and the car is again nearly undriveable. This time it's throwing P0420 (ineff. cat) and P0304 (misfire in cyl4). Any …633. 176K views 8 years ago. This low kilometer Subaru Impreza flags a P0420 Catalyst efficiency fault code very quickly. The rear O2 sensor would behave almost like the catalytic converter had...Subaru Mechanic: Ronnie. Normally you can replace the front converter without having to replace the downstream converter with no issue. The common one to fail and set the P0420 is, in fact, the front converter. If the only code your getting is the P0420 then I would just replace the front converter and usually, you will be fine with no issue.#1 · Apr 10, 2011. Hey all, new to the fourm. I have a 03 2.5 xs with about 135k. The cel fires two identical p0420 codes about once a week. I have done a visual inspection and …4 days, 1 subaru wideband sensor, and 3 drive cycles later, I have clearing subaru readiness monitors down to a T. And the wide-band that came with my AEM failsafe gauge is looks to be the same model as the subaru wideband, except the resistors are different. But, the P0420 code was still there.I have this in both my subarus more than a dozen times. Nothing was wrong with the car, the benzin (petrol) was either low octane (lower than the minimum recommended 95) or it had lead for some reason.The P0420 code is for low cat efficiency. It is unrelated to the cruise control, although the cruise light will blink (and the cruise control is disabled) on any CEL. I would say it was simply an odd coincidence (unless your car is possessed by an evil spirit). KianLM said: I also developed a head gasket leak.It usually gets you closer than a magic eight ball would. The short version of this is that P0026 is never due to a loose gas cap, 'bad' gas, vacuum leak, etc, unfortunately. It could be low oil, inappropriate oil viscosity, irregular maintenance, sensors, solenoids, wiring, possibly heads, etc. Like.Esta página está pensada para ayudarte a solucionar los problemas de Código de avería P0420 del Subaru Forester. Cubre el significado de Subaru Forester P0420, los síntomas, las causas y las posibles soluciones. En el Forester, el OBDII P0420 suele estar causado por un sensor de oxígeno defectuoso, pero también puede haber otras causas.If it's not there, drive the car down the street for a few minutes, or until the light comes on and check the fault in the VDCCM. If it's C0057 again, replace the VDCCM/ABS module. If you're in Austin, TX and having difficulties with the dealer or any shop, hit me up. P0420 Diagnosis. Sleeper vdc.Check engine light - P0420. I have an 2005 subaru forester with 82000 miles and the Check engine light is on and cruise control is flashing took it to the dealer and they replace the oxygen sensor after driving the car for about 20 mins the lights came back on.Any ideas on what should I do need help. So I went out and bought an OBD 2 scanner ...2.5x_sleeper. 45784 posts · Joined 2007. #6 · Dec 10, 2016. The O2 senor has a heater & if that's faulty, you'd get a specific code pointing to that fault. :wink: If you're getting a P0420 CEL code, the rear O2 sensor is detecting too much O2 in the exhaust flow.P0420 - Catalyst System Efficiency Below Threshold Bank 1. P0441 - EVAP System Incorrect Purge Flow. P0446 - EVAP System Vent Control Circuit. P0455 - EVAP System Leak Detected - Large Leak.When it comes to hardwood plywood and hardwood veneer products in North America, Columbia Forest Products is by far the most recognizable name in the Expert Advice On Improving You...Hi guys.. I too have the same code P0420 on my '01 Forester L, 120K miles. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less . Full Forum Listing.Master. 560 Answers. P0420 is one of two things, it is either a catalyst failure (below threshold) or rear lambda. The rear lambda should have a steady waveform when the engine is running if not then P0420 will be stored. Cats and lambdas are very common on Subaru.The connection to your P0420 isn't an obvious one (at least to me). Typically the problems associated with a bad PCV valve is that you end up with a mildly pressurized crankcase rather than one below atmosphere, and you push oil out from your valve cover gaskets or spark plug tubes. '19 Forester Premium, '18 Forester Limited, '15 Toyota Sienna ...P0420 code is the rear sensor reading the O2 levels coming out of the cat are higher than what should be. (possible failing Cat) good sensor. P0136 is the computer reading a problem with the sensor. Just did a PO136 on a ladies 2001 Forester. Changed rear sensor for $124 for part from Subaru and 20 minutes labor.So I installed the $5 mechanical fix for P0420 and now have P2096 (Post cat too lean.) I use both spacers the one connected to the O2 sensor drilled, ... We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.P0420 Subaru: Code Meaning, Causes, Symptoms, & Tech Notes The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability ...He has many many used foresters for sale and probably has a rebuilt engine ready to go or he can do yours. He is comparably cheap. Ph-717-426-4142. Tell him Al Conrad sent you. The other guy is every bit as good but a bit more expensive and probably doesn't have a rebuilt. He is Subaguru 717-786-2304.I've got a 2015 Subaru Forester with 175k miles that runs great but the other day all my dash warning lights went off. I checked the codes and it shows P0700 & P2764 and from a little research online it looks like I need a new transmission valve body. I've erased the codes several times and with each time the first time the car goes from 1st to ...The P0420 is a finicky code. There is a range of "acceptable" parameters that Subaru has set. If the O2 sensor sees a value that is outside of that range, even for just a fraction of a second, you get the P0420. Adding the extension doesn't stop the O2 sensor from working, it just doesn't get the immediate read, but more of a mixed read.2.5x_sleeper. 45859 posts · Joined 2007. #5 · May 29, 2023. @Highest_Harvest looks like low end is around $300, upward to over $500 on RockAuto, as the front CAT & headers are one piece. Normally a P0420 CEL code is caused by too much O2 in the exhaust flow from the engine running too rich.P0420 is a major money maker for Subaru mechanics... When the rear O2 sensor measurements are our of the very narrow acceptable values, it will throw the P0420 code. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.P0420 is a diabolical code that IMO is best viewed with suspicion. ... We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the …After reading most if not all of Cardoc's 1000+ page bible on the P0420 codes, and doing much of the testing (as best I could), I thought I'd ask for a bit of advise. ... 2009 Forester 2008 Outback 2.5i 130K PIA, 2010 Outback 2.5 103K, 139K, 156K, 192K ... I guess first / next step is to get an O2 sensor and a real live Subaru AF sensor. That ...How To Address a Subaru P0420 (Step by Step) NSUGS. 162 subscribers. Subscribed. 260. 16K views 1 year ago. The nerdy and keen eyed will notice I omitted …Shortly after we bought our 2005 Impreza Outback Sport with 253K miles last summer it started throwing P0420 codes and after a reset, the code returns after 8- 10 miles. On our 2003 Forester we bought a year ago at 223k miles, it threw a P0420 earlier this year, then again about two weeks ago. I ...Hello everyone! Received this p0028 code on my 08 ll bean forester last weekend when going up to the mountain. Didn't notice any issue running until I had to climb a pretty steep hill and rpms went over 4K. The car was physically shaking back and forth like it was going to stall until I took my foot off the gas a bit and brought rpms down.The P0420 code is a diagnostic trouble code (DTC) related to the efficiency of the catalytic converter. This code appears when the vehicle's engine control module (ECM) detects that the catalytic converter is not functioning as efficiently as it should, based on the readings from the oxygen sensors located before and after the converter.Why not? In my experience, a P0420 is more a code to prove a bad rear O2 sensor than an actual innefficient cat. How do I know? I threw a P0420 constantly in my …I'm new in here and I have my first Subaru car. I would appreciate if somebody could help me. I have Subaru Forester 2.0 Diesel engine, model 2012 (European model). Last few months I have same problem. Traction control and check engine lights are on and Crusoe control light is blinking. I have OBD2 reader and pro software. When I scan it shows:There's some good information from that post onward. The gist of these messages and, I've fixed a P0420 four times on three different Subarus by merely replacing the downstream O2 sensor. (It, 31 posts · Joined 2006. #1 · Feb 19, 2008. I originally posted a, However, moving forward two months a DTC P0420 popped up. O2, I've fixed a P0420 four times on three different Subarus by merely replacing the downstream O2 sensor., Just a note...P0420 codes are typically caused by faulty catalytic conv, Mar 21, 2011 · I figure I'd give this thread a quick update. We did the catalyti, The P0420 is a finicky code. There is a range of "accept, So heres my issue, I have a 2004 Subaru forester X with , CLEAN Your CAT - Fix stubborn P0420 Here's what I did: On 2, p0420 road test I got the subaru procedure for the p, The P0420 CEL code come from that sensor! Here's another link to, I have a 2011 2.5x (65k miles) and the CEL light came on, HELP: Code P0420. My 2009 forester has the “cruise” l, Also, P0420 can be the cat, but it can be a number of ot, Recently the check engine light has come on and is showing th, P0420 definition: Catalyst system efficiency below threshold (Ba, All O2 sensor and cat-related (P0420, P015A, P015B). It was .