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I was way over mileage for my cat to be covered under its warranty. Trust me I checked every solution to fix this before spending the money on a cat converter. i was up to 99K miles when the check engine light came on, so i figure i was due for the cat coverter. I couldnt find a way to get rid of the code until i came across an article on the sensitivity of the check engine code and how the ECM needed a reflash, problem solved......FINALLY!
I was way over mileage for my cat to be covered under its warranty. Trust me I checked every solution to fix this before spending the money on a cat converter. i was up to 99K miles when the check engine light came on, so i figure i was due for the cat coverter. I couldnt find a way to get rid of the code until i came across an article on the sensitivity of the check engine code and how the ECM needed a reflash, problem solved......FINALLY!
Does anybody happen to know if the REFLASH is available for the 2.8 motor? im getting a intermittent p0420 and an intermittent code for pre cat 02 sensor bank 1. i have a 01 a6 2.8 fwd. i would like to get this reflash so i can get rid of the code. (no MIL just stored code)
My check engine light came back on after the reflash. So now I officially have NO idea what the hell is going on with the P0420 code on this car. It does happen as i drive for long periods of time meaning on long stretches of road without stopping. Thinking that the O2 sensors are reading a high temperature and then throws the code. Been trying a trial and error approach as I've been resetting the code with my code reader and finding out when the check engine light comes back on. I'm REALLY trying to avoid the Audi dealership as we're all trying to save a penny here and there now a days. I've changed a lot of items pertaining to this code as stated before. The only thing I could think of is 2 of my spark plug coils are a different brand than from the OEM replacements that I put in there since I had two burn up on me. Any help please!!!!
I did another inspection on the cat that was replaced on my car while the car was in my garage. I plugged both exhaust with a rag and made a heavy soapy mix in a squirt bottle. I turned on the car and doused the cat with the soapy mix. Found that there was a crack in the weld of the cat. I assume that this crack is taking In an influx of O2 into the cat and giving the sensors a bad reading. Getting the cat replaced under warranty since it was put on recently (within a year). Here's to really hoping that this is going to get rid of the CEL p0420 code that has been haunting me for almost a year! I'll repost in another couple weeks with the outcome.
I was going to ask if your "new" O2 sensors were exact bosch OE replacements or generic? I've had problems with 75% of the non exact OE aftermarket O2 sensors I've purchased; typically a "heater circuit" error but none the less, gernerics seem problematic in VW/Audi, both 4 and 6 cylinder.
I was going to ask if your "new" O2 sensors were exact bosch OE replacements or generic? I've had problems with 75% of the non exact OE aftermarket O2 sensors I've purchased; typically a "heater circuit" error but none the less, gernerics seem problematic in VW/Audi, both 4 and 6 cylinder.
Hey Mark,
The O2 sensors were the Bosch OE replacements bought from an audi authorized dealer for VW/Audi cars. So unless they are at fault (even after a good voltage reading) I wouldn't have a doubt. But thanks for advice. Should have the new cat put on sometime this week. Hopefully it cures this damn light.
Have you find any solutiins for this?
I bought recently A6 Avant with ARS engine (4.2 V8), after 1500miles i get P0430 with every 300miles. 1st i used OBD2 reader, but today i got VCDS(VAG-COM) and there is 2 faults now:
I captured some data from O2 sensors, bank 1 sensor 2 seems to be dead, or getting lot of air..
ASG 4.2 V8 juniku O2 sensor P0430 P1176
400miles before problems started, i started to use Shell V NitroPower instead of RE95, i dont know did it have anything to do with it, but next fill-up will be RE95, i will take car to to emission tests in early next week.
I"m undergoing a similar Code 0420 situation. Does anyone have resolution on how they got rid of this?
front and rear 02, cat, flow meter and even fuel filter changed....
not sure of my next step. I dont want to have to flash the ecu..
P0420 NIGHTMARE!!!!
I have no other ideas on where to go with this. I practically changed every part that has to do with this damn code and have not received any type of relief. I mean granted I thank this website and everyone’s input to getting rid of this code, but still cant get it to go away. I don’t want to take it to the dealer because it would cost me a fortune and believe it or not im under budget from taking it to the damn audi dealership and having them charge me 180.00 as a diagnostic fee. So after doing long time research on this code on the internet, I have replaced the following:
Both o2 sensors
Spark plugs
Spark plug wires (Thank you audi for the recall on the wires)
Spark plug coils
Vacuum tube toward the rear of the engine that I found cracked.
Cat converter
I left the Cat for last since it was the most expensive part to replace and I broke down and went with the repair only to find out that a couple days later “Ding” f-in engine light comes back on to give me the same code – p0420 (Autozone reading). Damn this code right to hell!!! I also read on the possible outcomes that this code can be tripped by a leak in the intake, is there a way that I could possibly detect that? I would like to take pride and be able to fix my own car, hence the other reason why I didn’t want to take it into the stealership. I have a 2002 Audi A4 1.8T for those that might have a further solution. Im on my last leg here on trying to figure this out and im about to punch my dash if I see this check engine light any LONGER!! Lol. Can someone throw me a bone here.
Respectfully, Pissed off Audi owner.
Note: I don’t think I’ve gone more than a month without this engine light going off. Next car = NOT AN AUDI!!
01-16-2012, 04:17 AM
