cat rattle

[diztek]

anyone know if my internals in my cat are rattling, would that throw a cel?

[dougyfresh]

I don't think it will throw a CEL. My HFC came loose and I never had a CEL.

You sure its the cat and not the exhaust piping rattling on something?

[diztek]

ya pretty sure, i had it on the lift and i checked the whole exhaust and heat shields. also checked the both intercoolers. and i replaced my motor mounts and snub.

the rattle is most noticeable in 2nd and 3rd gear. for example as soon as i shift into 3rd, i give it gas and about 2 seconds later i hear a quick rattle. after i hear the rattle, ill coast (still in 3rd gear) and let the rpms go down, then ill accelerate again and 2 seconds later ill hear the rattle again. only happens in the beginning of acceleration in 1st, 2nd & 3rd gear. i kinda was hoping it was the internals inside the cat, cuz that's the only thing left covered under warranty.

im wondering if Audi will attempt do fix it w/out a cel?

[dougyfresh]

I heard mine around 2500-3000rpm. I also had a 3inch downpipe with High Flow Cat. I went to a 2.5inch downpipe with HFC and have had no problems. The thought there being the 3" downpipe had a lot of backpressure that blew out the cat since my entire exhaust is 2.5".

[diztek]

thanks. i know the cat is covered for 8 yrs 80k miles. i think im gonna take it to the dealership and hopefully they can look at it and if it is the cat, hopefully they will replace it even though it is attached to an AWE exhaust.

[kwimberly]

thanks. i know the cat is covered for 8 yrs 80k miles. i think im gonna take it to the dealership and hopefully they can look at it and if it is the cat, hopefully they will replace it even though it is attached to an AWE exhaust.

Those are the exact symptoms my old Jetta had when the cat busted. Like you said - it was the last thing remaining under my warranty!

[zims666]

the rattle is most noticeable in 2nd and 3rd gear. for example as soon as i shift into 3rd, i give it gas and about 2 seconds later i hear a quick rattle. after i hear the rattle, ill coast (still in 3rd gear) and let the rpms go down, then ill accelerate again and 2 seconds later ill hear the rattle again. only happens in the beginning of acceleration in 1st, 2nd & 3rd gear. i kinda was hoping it was the internals inside the cat, cuz that's the only thing left covered under warranty.

im wondering if Audi will attempt do fix it w/out a cel?

had the same symptoms.
mine was under warranty, no CEL, and the stealership replaced loose/rusted exhaust mounting hardware:

silencer -- part#:8E0-253-609-KD AU
clamp -- part#:1H0-253-141-B AU

hope this helps

[diztek]

hey thanks. it ended up not being the cat. ill have to check out the parts you mentioned. much thanks.

[psuaudi]

did you ever get a solution?

[boostedAvant]

Haha, when I installed my test pipe I shook my cat around and I could feel the internals moving around, I never tripped the MIL though. I think clogging will trip the MIL more then this. The cat can still work if its a little loose/split internally, I feel like most of the dimples (Whatever you want to call them) will still do their job.

[BNZ TOY]

My cat was replaced by the dealer when i brought it in to find out what was rattling under the car. The cat has disentegrated on the inside, haha. I have a TP now.