P0420 Catalytic Converter Efficiency and C1424 ECM Module Fault are the 2 constants; they have been there every time. As a quick educated guess I am going to say the catalytic converter is failing and sets the ECM fault at the same time. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester ...Potential Causes of the P0420 Code. Several issues can trigger the P0420 code in your Subaru Forester: Faulty Catalytic Converter: The most common cause, often due to …How does a forest fire benefit living things? Learn how a forest fire benefits living things at HowStuffWorks. Advertisement Car fueled, cruise control set and audiobook in play, I...The P0420 code can actually point to a lot of different things. In a rush to head out of town, I got an oil change at a subpar quick lube place, and got a P0420 code about 100 miles down the road. Took it over to a buddy's place when we got back into town, and he said "this cheap oil filter is probably throwing the code".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.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.This Service Information Bulletin announces diagnostic service procedures to be followed when DTC P0420 (Catalyst System Eficiency Below Threshold Bank 1) is detected by …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.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.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.Oct 18, 2008 · B. bdubbs84 Discussion starter. 13 posts · Joined 2008. #7 · Oct 20, 2008 (Edited) Well, I got rid of the P0420 catalyst code, but now I have two new codes. One is P0440 (Evap. Emission Control System Malfunction) and the other is P0136 (O2 Sensor Circuit Malfunction, Bank 1 Sensor 2). I already have the O2 sensor spacer in place.It's a 2012 forester premium. In the last year she had the engine gaskets replaced. Then the catalytic converter, the alternator, radiator and battery. So she was over it and gave it to me. I had to drive it from Louisville to Wisconsin. And a couple hours in the check engine, traction control light (both solid) and cruise control light ...P0420 Cat below threshold, this has failed due to rich fuel mixture caused by mass air flow sensor and this also damaged the AF sensor. Rear O2 is reading, on removal sensor may be contaminated and if so recommend replacement. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications ...The P0420 is the only code and it just started. The last on the VIN are 4H748003. There are no exhaust leaks that I am aware of and I have taken excellent care of my baby. I have not noticed a drop in milage, as I am still consistantly geting 24 MPG. I am thinking about trying to replace the O2 Sensors before replacing the Cat.2006 - P0420 code and O2 sensor value at 2,8V? ('06-'08) Jump to Latest Follow 630 views 2 replies 2 participants last post by syl20.m ...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.Like I said in the thread title, the P0420 CEL has been on since last September or so. It never really affected the performance of the car other than a slightly lower gas mileage so I was never really bothered. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability ...Hard shifts, jerking under load, P0420 engine code after new timing belt/water pump ... I have a 2001 Subaru Forester (Auto) with 138,393 miles on it. With some help, I replaced the water pump and timing belt a few days ago. I followed all instructions for setting the timing. However, I immediately noticed that the shifts were harder ...Here are the most common causes of P0455. How your Forester's EVAP system works will depend on the model year and engine type.. Evap System Hose- The EVAP hose carries fuel vapor from the fuel tank to the intake manifold can begin to leak.This will cause the P0455 code. Look for either a tear or in the hose.Five trim levels are available on the 2020 Subaru Forester: base, Premium, Sport, Limited and Touring. All models come standard with all-wheel drive, and the only engine is a 2.5-liter four ...P0420 Cat below threshold, this has failed due to rich fuel mixture caused by mass air flow sensor and this also damaged the AF sensor. Rear O2 is reading, on removal sensor may be contaminated and if so recommend replacement. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications ...Bluedriver diagnostic tool: https://amzn.to/2Vk2XjjO2 sensor socket: https://amzn.to/2TexLPPFixing the P0420 code is easy. First, make sure you're all cau...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.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... www.subaruforester.org.2001 Subaru Outback LLBean P0420 Diag - YouTube ... I was also reminded why I opted out of owning a Forester. You can't just tilt the seat up to get to the harness, and too much to remove from the rear to get to the fuel pump. But it all worked out good. If you're in Austin, TX and having difficulties with the dealer or any shop, hit me up. ...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.in this video I will share with you how to diagnose and fix the cause of a P0420 and P0430 Trouble Code on a Hyundai Sonata#Catalyticconverters #Catalyticcon...I recently purchased a 2005 Subaru Forester XS, and it's beautiful! But after driving it 30 miles, the CEL popped on & the Cruise Control Light started blinking. I got home and plugged in my reader to find out it was the lovely P0420. After reading the live data, I saw my "Oxygen Sensor Current (B1-S1)" fluctuates between -127.918 mA & 127.871 mA.2.5x_sleeper. 45859 posts · Joined 2007. #2 · May 17, 2020. @Jaime ochoa welcome to the forum from Oregon! The P0420 CEL code is from the rear O2 sensor, but that doesn't mean the sensor is bad. The rear O2 sensor is monitoring for excess 02 in the exhaust flow, so the fault could be something upstream... even a pinhole leak in the exhaust ...Jul 24, 2020 · 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.P0420 code I have an 03 Forster with 135k mi on it. ... 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.Aug 24, 2022 · 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... www.subaruforester.org.The P0420 CEL code come from that sensor! Here's another link to check out. P0141 Subaru: Code Meaning, Causes, Symptoms, & Tech Notes (With Video) ... 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.I have a 2010 Subaru Forester Premium Plus PZEV that is. I have a 2010 Subaru Forester Premium Plus PZEV that is setting a P0420 code. Dealer says catalytic converter is bad and need replaced along with A/F sensor, which I'm assuming is the oxygen sensor. I'm repairing it myself by replacing the upstream cat with a new CARB compliant cat from ...Forester. SỨC MẠNH ĐỘNG CƠ. Thiết kế phẳng nằm ngang của động cơ Boxer mang lại sự cân bằng và khả năng kiểm soát tối ưu với trọng tâm thấp, đây là sự khác biệt độc đáo cho khả năng vân hành hiệu quả được Subaru sử dụng trong hơn 50 năm qua. TÌM HIỂU THÊM.If the upstream and downstream oxygen sensors determine that one of your Forester's catalytic converters is not doing its job properly, it'll throw the trouble codes P0420, or P0430 respectively. If you have this code AND the smell of rotten eggs, it is very strong evidence that the catalytic converter is bad. DiagnosisHi guys. New to the forums. Just bought a 2005 Forester XS N/A and I too have the dreaded P0420. Previous owner had the catalytic converter replaced before I bough the car so I didn't think it would be a bad cat. Got under the car this weekend and found an exhaust leak where the catalytic converter bolts to the y pipe.In all seriousness, the P0420 is only good for making your wallet lighter by either ~$100 for a new sensor or several times that for a new 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.Nov 30, 2020 · PO420 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.Here are the most common causes of P0420 in the Subaru Forester: Likely Causes. Bad catalytic converter; Bad O2 sensor; Other Causes. Exhaust leak; O2 sensor wiring; PCM issue; Overheating converter (usually caused by a misfiring engine, there should be codes) Burning oil (overheats converter, usually no code) Engine not heating up enoughHere is my story. I have an 01 S with manual trans with 227,000 kms. Forester has always been maintained at the dealer. This past winter I started getting an intermittent P0420 code. If i used premium gas it triggered every 3 weeks or so. If i used regular gas it tripped pretty much once a week ( i fill up approx every 5 days).P0420: Catalyst System Efficiency Below Threshold; P0421: Warm Up Catalyst Efficiency Below Threshold; What Does It Mean? Your vehicle is equipped with at least one oxygen sensor, and if your vehicle is newer than 1995, multiple oxygen sensors that monitor the output of your exhaust system. This sensor is designed to monitor oxygen in the ...P0420 Subaru Catalyst System Efficiency Below Threshold Bank 1. As the code description implies the P0421 Subaru code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the ...How to diagnose code P0420 on a Subaru Forester. Typically, you'll find out about P0420 because your malfunction indicator lamp or "check engine light" turned on & you or a mechanic diagnosed the problem with an OBD II code scanner like this one from Bluedriver. You may experience a very slight reduction in engine power from reduced exhaust ...NO, P0420 code started BEFORE the exhaust work, has been CEL since I got the car. The P2096 code started some time after the $5 fix AND the exhaust work. I think it is pretty clear that the P2096 is related to the fix, as it would make sense if the O2 sensor is backed out of the exhaust stream that it would "think" it is running lean.My 2011 Forester keep throwing the P04020 code. I reset and it's back in a few days. P0420 Catalyst Efficiency Below Threshold So I get under the car, there are no sensors or wires going to any part of the exhaust system from the engine back. Don't see any oxygen sensor on the pipe. Not sure what is going on.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.The cat issue can be dealt with later. If a vehicle is throwing a P0420 only, it should still run well, or at least can be made to run well. 2005 FX 2006 FXT 2012 FXT. ... 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.The P0420 is actually being caused by the downstream O2 sensor getting a reading it doesn't like. In all fairness, that could be because the exhaust going into the cat to begin with. ... 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 ...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...I have a 2011 2.5x (65k miles) and the CEL light came on after filling up with gas a few weeks ago. I checked to make sure gas cap was tight and CEL was still on. I had the codes read and it showed P0171 & P0420. I reset the codes to see if it might have just been the gas cap, but CEL came back on. I've noticed a decrease in gas efficiency ...Subaru Forester Owners Forum is a community of enthusiasts who share their experiences, tips, and advice on the best Subaru Forester models, modifications, and reliability. Join the discussion, browse the forums, …2005 Forester bought last year for my son who is in school about 3 hours away. Chasing a re-occurring P0420 code, I have replaced or checked the following: PCV valve – OEM – original valve was not clogged Plugs – NKG – removed plugs looked good, no evidence of oil or unusual wear. Wires- NKG Front and Rear 02 sensors – DensoP0065 IS an Air assist failure. The re flash lowers the threshold as detected by the MAP when the valve opens. If it is an electrical failure of the coil, it would be a P0066. But P0065 is a failure of the MAP to see a manifold vacuum change when the ECU signals the Air Assist valve to open.Subaru Forester Owners Forum. 2.6M posts 191.3K 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. Show Less . Full Forum Listing. Explore Our Forums ...1. Visit autoshop and have them repair it by cleaning and/or replacing the parts. Total estimated cost is $900+. This will only reset the imaginary timer for it to re-occur again in the future. 2. Buy Accessport ( link) ~$400 used/$600 new and TGV delete kit ( link) $68.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 ...Dec 23, 2015 · 32 posts · Joined 2015. #11 · Dec 24, 2015 (Edited) P0420 - need some specific help. From what I understand, that rear o2 sensor waveform in the third picture is classic sign of a bad cat. It's likely that waveform that is triggering the code. The others look more stable, unless the scale is off. But the rear still mirrors the front.The P0420 code is set by a reading from the downstream O2 sensor. That's all that the downstream O2 sensor does, is monitor the efficiency of the 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.The P0457 is one of the codes that triggers the CEL only if the fault is detected in two driving cycles. The CEL will go out if the fault isn't detected for three driving cycles, and the code is erased from memory if the fault isn't detected for 40 driving cycles. This can lead to frustration if the fault is intermittent, because by the time ...The codes are: P0420: Catalyst System Efficiency Below Threshold (bank 1) P0422: EVAP Control System Leak Detected (Small Leak) I am now in a new area and went to a mechanic who wasn't familiar with my vehicle history. I explained my situation and mentioned to Rear O2 sensor issue of the past. This mechanic read the codes and said that it was ...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 more4 posts · Joined 2023. #1 · Jan 13, 2023. I have a 2009 subaru outback 2.5. I am replacing the fuel pump. The one in the car has 2 fuel line connections, 1 on top of fp housing and 1 below in the tank connection. The replacement pump has both fuel connections on the top. I can't seem to find the pump I need anywhere.Finally, I haven't changed the spark plugs yet. I took the Forester over to AutoZone to check the codes. It came back P0171 (three different P0171 codes). Here are the details: Troubleshooting P0171. System too lean - bank 1 (cylinder number 1 denotes bank 1) Probable Cause. 1) Faulty MAF Sensor.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 moreMy 2011 Forester keep throwing the P04020 code. I reset and it's back in a few days. P0420 Catalyst Efficiency Below Threshold So I get under the car, there are no sensors or wires going to any part of the exhaust system from the engine back. Don't see any oxygen sensor on the pipe. Not sure what is going on.Conclusion. The P0420 code is an indicator of a problem with the catalytic converter in your Subaru. Common causes can include failed or malfunctioning components, such as the oxygen sensor, fuel system, EGR system, and exhaust system. It's best to take your vehicle to a professional mechanic for diagnosis and repairs.Subaru 2007 Forester, now 138k miles. Above condition began intermittently Novemeber 2014. No obvious driving performance issues. In September 2014 had major maintenance performed by Subaru dealer. ... As for the P0420, you could remove the catalytic converter and clean it with citrus cleaner. There are numerous threads on this, but basically ...Right after I got the new PAK file, my car threw a 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. Show Less . Full Forum Listing.05/22/2024. When your 2019 Subaru Forester triggers a P0420 code, it typically indicates a problem with the vehicle's exhaust system, specifically the catalytic converter 's ability to reduce emissions. To resolve the issue, you'll need to identify the root cause, which could be a faulty oxygen sensor, blocked or clogged converter, or unburned ...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.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... www.subaruforester.org.