i think my cat is clogged, can i just drop it to find out?

jenyus425 · 04-30-2012, 05:12 PM

i think one of my cats is clogged. rotten egg smell from one of the pipes. can i just drop the cat on the side that i think is clogged and run it like that to test? will that cause the car to go into limp mode or anything? im not talking about driving it like that for long, just to see if my power comes back and overheating go away

GTA_Driver · 04-30-2012, 05:13 PM

No. You cannot just drop a cat. It is part of the downpipe/header.

And I doubt your cat is clogged. What kind of gas do you put in your car? What engine?

jenyus425 · 04-30-2012, 05:15 PM

i thought that the rotten egg smell from the tail pipe meant that the cat is bad, why can't i just run the straight pipe from the turbo for a couple minutes?
ive got the 2.7t

i put premium in it, but ive only had the car for a few months and its had this problem since i got it.

jenyus425 · 04-30-2012, 05:27 PM

sorry i meant why cant i just drop my downpipe?

ezveedub · 04-30-2012, 06:35 PM

Rotten egg smell means you ran fuel with sulphur in it. You may need to run a different brand fuel and add fuel additives to your tank. Make sure your engine is is running properly also, as poor combustion from needing a tune-up can also cause this. A good highway run will help to clear out loaded up cats sometimes also.

jenyus425 · 05-01-2012, 01:43 PM

well im really running out of ideas, the car has almost no power, im getting about 10mpg and it overheats but still making 7-11 lbs of boost. but theres a small coolant leak in one turbocharger, when i do a pressure test i can hear air bubbling up from around that turbocharger area.

Pchelka01 · 05-01-2012, 02:58 PM

Have you checked for any soft codes?

jenyus425 · 05-02-2012, 01:11 AM

Quote:

Originally Posted by Pchelka01

Have you checked for any soft codes?

you mean with the vag com? 034 motorsports did it for me and it came up with some minor valve body codes for the tranny and thats it. they did say its running lean though

GTA_Driver · 05-02-2012, 11:48 AM

So there are no codes, and the car runs like crap?

While it's possible that someone did some serious carbon buildup removal, and chunks of carbon now clogged your cat, I doubt it.

Rotten egg smell indicates a large presence of sulphur. As another suggestion, put a can of seafoam into your gas tank, then fill up, and drive the car for a while, see if anything helps.

If you drop your downpipe, you will have a very loud exhaust, since your are dropping the exhaust right after the turbo outlet. You will have O2 sensor codes, and the other side will put up greater exhaust resistance than this one. Seems like a strange way of testing the cat, but if you have the tools and the skills to drop the downpipe, the time and the place, I guess you could go for it.

jenyus425 · 05-02-2012, 12:00 PM

cool ill try the seafoam. ill take both of the downpipes off when i do it to test. i know it will be stupid loud but at least then i'll know. my dads got a 6 car garage with an oil pit so removal isn't a big deal. i guess i could get a laser thermometer and get temp readings with that, that would probably be a lot easier, if one side is clogged it'll be hotter im sure, right?

05-02-2012, 11:48 AM	#9
GTA_Driver AudiWorld Super User 2005 Audi Allroad Join Date: Aug 2004 Location: Toronto Posts: 2,575	So there are no codes, and the car runs like crap? While it's possible that someone did some serious carbon buildup removal, and chunks of carbon now clogged your cat, I doubt it. Rotten egg smell indicates a large presence of sulphur. As another suggestion, put a can of seafoam into your gas tank, then fill up, and drive the car for a while, see if anything helps. If you drop your downpipe, you will have a very loud exhaust, since your are dropping the exhaust right after the turbo outlet. You will have O2 sensor codes, and the other side will put up greater exhaust resistance than this one. Seems like a strange way of testing the cat, but if you have the tools and the skills to drop the downpipe, the time and the place, I guess you could go for it. __________________ 2005 AR 2.7 Black: GIAC tune, 710N, H-sport sway bars, Depo LED taillights, akebono pads delete Past Audis: 2001 A6 4.2 \| 2001 A4 1.8T Quattro \| 1993 100 CS Quattro \| 1984 5000 CD turbo FWD

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04-30-2012, 05:13 PM	#2
GTA_Driver AudiWorld Super User 2005 Audi Allroad Join Date: Aug 2004 Location: Toronto Posts: 2,575	No. You cannot just drop a cat. It is part of the downpipe/header. And I doubt your cat is clogged. What kind of gas do you put in your car? What engine?

04-30-2012, 05:15 PM	#3
jenyus425 Audiworld Junior Member Garage is empty, add now Join Date: Jan 2012 Posts: 33	i thought that the rotten egg smell from the tail pipe meant that the cat is bad, why can't i just run the straight pipe from the turbo for a couple minutes? ive got the 2.7t i put premium in it, but ive only had the car for a few months and its had this problem since i got it.

04-30-2012, 05:27 PM	#4
jenyus425 Audiworld Junior Member Garage is empty, add now Join Date: Jan 2012 Posts: 33	sorry i meant why cant i just drop my downpipe?

04-30-2012, 06:35 PM	#5
ezveedub AudiWorld Senior Member 2012 Audi Q5 My Garage Join Date: Mar 2005 Posts: 812	Rotten egg smell means you ran fuel with sulphur in it. You may need to run a different brand fuel and add fuel additives to your tank. Make sure your engine is is running properly also, as poor combustion from needing a tune-up can also cause this. A good highway run will help to clear out loaded up cats sometimes also.

05-01-2012, 01:43 PM	#6
jenyus425 Audiworld Junior Member Garage is empty, add now Join Date: Jan 2012 Posts: 33	well im really running out of ideas, the car has almost no power, im getting about 10mpg and it overheats but still making 7-11 lbs of boost. but theres a small coolant leak in one turbocharger, when i do a pressure test i can hear air bubbling up from around that turbocharger area.

05-01-2012, 02:58 PM	#7
Pchelka01 AudiWorld Member Garage is empty, add now Join Date: Oct 2010 Posts: 193	Have you checked for any soft codes?

05-02-2012, 12:00 PM	#10
jenyus425 Audiworld Junior Member Garage is empty, add now Join Date: Jan 2012 Posts: 33	cool ill try the seafoam. ill take both of the downpipes off when i do it to test. i know it will be stupid loud but at least then i'll know. my dads got a 6 car garage with an oil pit so removal isn't a big deal. i guess i could get a laser thermometer and get temp readings with that, that would probably be a lot easier, if one side is clogged it'll be hotter im sure, right?