Mz3bo

Hi,

Woo, just found out this was the best TT forum !! :

This is all about my OEm exhaust on my 996TT... Please no need to says "get aftermarket exhaust", I just don't want to (being very disppointed after a few of them)...

I have finished emptying my cats but some few small debris (from the cats) fallen into the oem exhaust chamber itself. There is no way to reach it. When I shake the entire exhaust system, I can hear a few of them... My question is, can I install it on the car and wot it so all the debris get out ? The debris, IMO, are not larger than 1/4 inch ...

Second, can some of those debris get sucked back trough the turbos all the way into the combustion chamber ? What are my chances it get happens ?

Opening the exhaust and rewelding it is not possible. All the cats inside walls has been polished and it is not very smooth...

Thanks
Bo

ebaker

I don't think there's any way it will be a problem.

C DeVito

The air paths for the intake side of the turbos and exhaust side are separated; so no the debris won't get sucked into the engine intake/combustion chambers. Beyond that the debris in the exhaust is downstream of the turbos and should never find their way back up the path to hurt the turbos. I doubt you'll be able to hear them over bumps, so other than providing some blockage of air flow in the exhaust, I think there is no problem leaving them there.

Carmen

evo911

ok wait u are worried about stuff going back upstream in the exhaust? im confused...

jugger911

You mean the side vents?

Mz3bo

No,

I've heard about "backpressure" and I was kinda worried...

C DeVito

If I understand this, to reduce exhaust backpressure he destroyed the element in the cats and vaccuumed out of the catalyst housing but some fell into the main exhaust plenum. Since he can't get the debris out through the cat housing he wants to hook it to the engine and blow it out using the engine's WOT airflow. He is concerned there is a return loop to the intake that would allow that debris to enter the engine.

Any WOT runs will probably not blow 1/4" debris out the exhaust pipe, it will just be stuck in the exhaust box. The smaller stuff might get blown out the exhaust; but not get sucked back into the car. That is no more likely than any other outside road dirt getting sucked in past the airfilter.

Mz3bo

Cdevito, you are correct.

I was wondering wat happend when you are at 6000k and upshift. At that point, when you release the gas pedal, what happens to the exhaust system, does it suck a "little" air back inside or does the air still flow toward the outside ?

99firehawk

it will suck a little air in, thats why o2 sensors need 18+ inhcs of pipe after them