CEL: Code P0421
Login  | |
|
|
|
|
|
RE: CEL: Code P0421 - 7/24/2007 1:38:44 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
Here is what i got from the factory repair manual.
P0421= Warm Up Catalyst Efficiency Below Threshold Bank 1
Its just a fancy way of saying you need a cat converter on the passenger's side, which on a 3.0L, is beyond a pain in the a**! Plus the cat costs over $1,000 alone.
The good news is you have less than 80 thousand miles so federal emmisions warranty will cover it free of charge so grab a beer and smile.
< Message edited by auditech79 -- 7/24/2007 1:40:07 PM >
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 7/24/2007 2:03:11 PM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
Thanks auditech!
I have been noticing for the past month or so that my car leaks under the passenger side just behind and to the left of the passenger side lower control arm and also along the exhaust pipe on the passenger side. The texture of the leaking liquid is not oily, it feels more watery. Do you think this has anything to do with the bad cat converter? Or is this a completetly different problem that I have to take care of seperately?
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 7/24/2007 2:21:40 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
Give it a quick taste, if it tastes like **** its water from the exhaust, if it tastes sweet its coolant.
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 7/24/2007 2:38:02 PM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
Are you serious? It won't make me sick? 
Anyway, does one mean better than the other...as in, if it tastes like water it is ok? But if it is sweet/coolant, the cat converter is broke?
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 7/24/2007 2:44:00 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
Nah, im not telling you to drink it LOL.
As for the water the cats/connetor clamps tend to leak water on our exhaust systems when they get older for some reason, but it should be better after the cat replacment.
If its coolant, take the rear engine over off and stick a flash light down there behind the motor and see if you can see red crusty looking stuff coming off the rear coolant crossover pipe.
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 7/24/2007 7:48:29 PM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
OK, I looked under the car after it was sitting for a few hours and I could still see very small puddles and wet patches under the car on the pavement which means it did not evaporate (so I am guessing it was not water), though it had stopped dripping.
Also the underside of the car has that wet look like an oil leak. I do not have a jack to raise up my car to look under it or into the back of the engine from the bottom (or did u ask me to look behind the engine by popping the hood?). Is there anything you guys can suggest based on the symptoms I described?
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 7/24/2007 8:49:47 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
Yeah, pop the hood and take off the rear engine cover, and look down at the back of the engine.
If you see red dried up coolant everywhere on the cross over pipe thats where its leaking.
Are any of your fluids low? P/S, coolant, oil?
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 7/25/2007 7:44:29 PM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
I looked behind the engine, but I didn't get a good look because I didn't have a flash light. Anyway, it looked real dirty, so it could be that the coolant is leaking, though my coolant level doesn't look low or anything.
Coming back to the check engine light, I have had a chance to do some research online and it looks like this error code P0421 was a common problem with the 2.8s. There was a factory 'suggested' service bulletin (called IC service action that came out in July 2005) that was basically a reflash of the ECU because the cat efficiency thresholds were set too high. A lot of people have said that their CELs went away after doing this. Do you think the dealer will do this ECU reflash on my 3.0 for free?
What if he tells me that the cats are not bad and only the oxygen sensors need replacing? What kinda money would I be looking at to change the O2 sensors?
< Message edited by saintforlife -- 7/25/2007 7:48:13 PM >
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 7/25/2007 7:51:26 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
Un-fortunately the re-flash only applies to the 2.7T, 2.8L and 4.2L engines.
The 3.0L cats have to be replaced as it stands right now, but don't worry about it, its free from the federal emmisions warranty.
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 7/25/2007 8:02:55 PM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
Auditech, how sure are you that it is my catalytic converter? From what I have read, very rarely do cats go bad especially at only 52k miles. Isn't there a possibility that my oxygen sensors have gone bad and are throwing up these codes?
I am asking you this because though the cats might be covered under the federal 8y/80k warranty, the oxygen sensors are most probably not covered. I am a bit worried about the cost that might be involved in replacing the O2 sensors.
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 7/25/2007 8:27:57 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
There is about a 5% chance of the O2 sensors being bad with that fault code, trust me its the cats, replaced over 100 3.0L cats in about 3 years and about 2 O2 sensors for that fault code.
It says in the manual if you have that code to replace the cat converters first, then diag any other problems that could occur.
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 7/25/2007 8:33:33 PM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
Do you think that the the dealer should replace both cat converters? I know if one is going, the other one can't be too far behind. Then again, I did get only error code P0421 (which I think is Bank 1 - passenger side). I did not get P0431 (Bank 2 - driver side) error, which means the dealer could technically refuse to replace the second cat.
Any thoughts on how the dealer might proceed with this? Did you had to deal with a situation like this?
< Message edited by saintforlife -- 7/25/2007 8:38:58 PM >
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 7/25/2007 8:36:19 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
By law they can't replace the other cat converter without the fault code, but your're right the other one probably will fail sometime in the future.
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 7/27/2007 10:18:22 AM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
Here are some pictures from under my car where it leaks. Just wondering if you can tell me what I am looking at here. Is this serious? Since I am going in for my service tomorrow, I might as well try to get this fixed.
http://i199.photobucket.com/albums/aa116/saintforlife/IMG_0479.jpg
http://i199.photobucket.com/albums/aa116/saintforlife/IMG_0481.jpg
Just figured out how to embed pictures in a post.........I had to try it in one of my posts 
< Message edited by saintforlife -- 7/27/2007 11:58:38 PM >
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 7/27/2007 12:41:46 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
 Ha ha it looks like its just water. On the passenger's side right? Been using you A/C lately?
Thats exactly where the drain for the evaporator drips out under the vehicle.
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 7/29/2007 12:28:47 AM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
Took my car to the dealer today. He said the procedure they follow for the cat convertor error code is this - they clear the code the first time. If the check engine light comes back on again, then they go in and replace the cats under the federal warranty. So the dealer cleared the code and guess what, after driving around the city today, it came back on again. I guess I will need the cats replaced after all. I hope I can convince them to replace both cats even though there is no code for bank 2.
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 7/29/2007 11:09:56 AM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
Ha ha, erase the code first huh? Thats funny, that just tells you how much they don't wanna do the cat converters on a 3.0L.
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 9/25/2007 8:41:12 PM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
Just to give this one a closure in case anyone is interested, the CEL came back on a couple of days after the dealer had cleared it. It was the same code P0421. Today the dealer replaced the faulty catalytic convertor under the federal 8 year/80,000 miles warranty. He also said that they cannot replace the other cat because it did not throw out any fault codes and he will be liable to Audi if he replaced a part that does not need replacing. Oh well.....I am not complaining. At least I don't have the annoying CEL staring at me anymore. Thanks auditech79!
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 9/27/2007 10:27:02 PM
|
|
|
formulagigi
Posts: 1076
Joined: 4/23/2007
Status: offline
|
good news, free cat!
I had that code on my old 2.8 and it was an O2 sensor. I was worried it was the cat as I did not know about any emission warranty then
_____________________________
 
2004 A6 Stg 2+ and 99 TJ...mod
|
|
|
|
|
RE: CEL: Code P0421 - 10/30/2007 2:37:41 PM
|
|
|
DallasA6
Posts: 11
Joined: 10/29/2007
Status: offline
|
If I had just known about this forum 6 months ago!!
I've had the same code. I bought my '03 A6 3.0 just a few months ago with 85K on it. Great car, great styling, better mileage than I expected. Overall I've been happy. However, a few weeks after buying the car the P0421 CEL code came up. I took it to the Audi dealer in Dallas who quoted $1600 to resolve the issue. In reading your post, I discovered that federal law which OF COURSE I just missed by 5K miles. Just my luck!
So to ensure I read everything correctly (and yes, AudiTech I did search, haha), either the cat needs to be replaced or it could be a bad O2 sensor?
Did 1600 sound high to you to resolve the issue?
What would a O2 replacement run? Perhaps I could try this less expensive alternative to see if it resolves the issue.
Anyway, I really enjoyed reading your post. Tasted any good water lately? That was funny...
Thanks, Collin
|
|
|
|
|
RE: CEL: Code P0421 - 10/30/2007 7:40:09 PM
|
|
|
auditech79
Posts: 4995
Joined: 2/24/2007
From: Sacramento, CA
Status: offline
|
quote:
ORIGINAL: DallasA6
If I had just known about this forum 6 months ago!!
I've had the same code. I bought my '03 A6 3.0 just a few months ago with 85K on it. Great car, great styling, better mileage than I expected. Overall I've been happy. However, a few weeks after buying the car the P0421 CEL code came up. I took it to the Audi dealer in Dallas who quoted $1600 to resolve the issue. In reading your post, I discovered that federal law which OF COURSE I just missed by 5K miles. Just my luck!
So to ensure I read everything correctly (and yes, AudiTech I did search, haha), either the cat needs to be replaced or it could be a bad O2 sensor?
Did 1600 sound high to you to resolve the issue?
What would a O2 replacement run? Perhaps I could try this less expensive alternative to see if it resolves the issue.
Anyway, I really enjoyed reading your post. Tasted any good water lately? That was funny...
Thanks, Collin
Yeah that sucks! Since your over 80k miles your gonna need that new cat converter, the cat itself costs over $1,000 and labor is around 4 hours, so i would estimate it at around $1,500
_____________________________
00 A4 1.8T
|
|
|
|
|
RE: CEL: Code P0421 - 11/18/2007 7:08:46 PM
|
|
|
COJAM
Posts: 24
Joined: 10/26/2007
Status: offline
|
Hey I have a 2000 2.7t with 79K am i covered under an emissions warranty? Code P0421
|
|
|
|
|
RE: CEL: Code P0421 - 11/26/2007 4:36:01 PM
|
|
|
saintforlife
Posts: 173
Joined: 3/4/2007
From: Houston, TX
Status: offline
|
You need to get it fixed ASAP. Once you go over 80k, you are no longer covered under the federal warranty.
_____________________________
2003 Audi A6 3.0 Quattro
Silver - Premium Package - Cold Weather Package - Bose - Passport 8500 X50
2006 Audi A3 2.0T 6MT (new car)
|
|
|
|
|
RE: CEL: Code P0421 - 1/3/2008 11:08:13 PM
|
|
|
nativecustoms
Posts: 10
Joined: 12/21/2007
Status: offline
|
Auditech, man your full of great advice! A real asset to this forum. :)
All you guys on this cat topic are beginning to worry me though. :( The 02 3.0 A6 with 120K miles I'm going to buy from a friend has the CEL on. He told me that its been coming on ever since the first owner had the car years ago. He said the 1st owner had the car to the dealership over 10 times in the 5 years he had the car, and they would clear it and then it would come back on. I'm getting 3rd hand info here, but from what my friend says, they never could put their finger on why the cel would come on. I will get the code asap before I buy. (maybe they didn't want to replace that cat under warranty and wanted to wait for the 80K to run out. Who knows.)
Is the VAG-com tool better for reading codes that the audi computer? Was thinking about investing in one to diagnose problems myself?
What I'd like to know is, and if the Fed's are listening I'm only talking hypothetically of course, can I replace the cats with straight pipe or maybe an aftermarket cat?
If need be, a bung could be welded in the straight pipe for the O2 sensor. Not sure if its in the cat or not since I haven't looked under the car yet. My friend owns a muffler shop and could get me a aftermarket way cheaper then 1000.00.
By the way. If anyone does have a cat replaced for whatever cost. Get the old one back. Old cats can be sold for scrap to the right place for big bucks! Like 100.00-200.00+! This is because there is precious metal in them to do the job they do. I think platinum or something. That's the story I got from my muffler shop owner friend. That will help offset the cost of your new cat if someone wants to go through the trouble. If not, then the repair shop will pocket the cash.
|
|
|
|
 Today's Posts
Most Active Topics
Make A Donation
Forum Rules & FAQ
RSS Feeds
Audi Prices
Audi Cars
Audi A6  Audi S3
Audi A4 Audi S4
Audi TT Audi S6
Audi Dealers
Audi Clubs
Advertising Info
|
Contact Us |
Link To Us |
Sitemap |
About AF |
Archive |
Advertising |
AudiForums.com Partners |
Audi Links |
Legal |
Privacy Policy |
Printable Version
CEL: Code P0421 - 
