jenyus425

so i used my laser thermometer when the car was running hot and checked both cats, they were both reading between 350 and 500 degrees before and after the cats. so i guess that rules out a clogged cat, what about a clogged muffler?

GTA_Driver

so even if one muffler is "clogged", the exhaust does cross-over (OK, at least it does on my 4.2, not sure about other engines).

One of my cats burned out and pieces of it are rattling inside the right side muffler. No impact performance-wise.

I suspect your issue is elsewhere, not a clogged exhaust.

You scanned the car with VAG-COM and saw NO codes?

jenyus425

i noticed that both pipes go into what looks like a resonator and then back out to the mufflers. but i didn't know if they crossed over or not. When 034 motorsports scanned with the vagcom they didnt find any errors other than a couple intermittent valve body codes. im really hesitant to buy a vagcom cuz i really don't want to throw any more money into the car, im just trying to sell it right now and cut my losses on it, but even having it priced at $5,200 no ones biting.

jenyus425

I dropped both cats today, just straight exhaust from the turbos, man that was noisy. Driver side cat was clogged, passenger seemed okay. What's the best way to check? I just did the light test, where u shine the flashlight through and see if you can see light or not. I can get to the little arms on the waste gates, should I be able to move them by hand to see if one is stuck?

Oh almost forgot, when straight piped today, I could hear turbo whine up to 2500 rpms (which is where I stop feeling boost) it seems like if the turbos were spooling correctly (waste gates not stuck) that I should hear the whine all through the power band, right? When in park, I can rev all the way to redline and hear turbo whine.

My dads got a 6 car garage with an oil pit so it's pretty easy to get under it and do stuff.

Also found a weld on passenger side turbo housing fml

Sgt G

Yes u should be able to move waste gates by hand, theres a spring inside them that compresses at factory predetermined max boost level to to bleed off excess boost. So, you should be able to move them, there should be tension on the wastgate rod. If you don't find tension, your wastegate may have a broken internal spring (doubtful, but possible).

FWIW; most waste gate rods are set with a small lock nut at the base of the housing, form a performance perspective; it's also possible to gain more boost by loosening this nut / /fitting and shortening the rod (2 full turns is plenty lol) if you desire car to boost higher before waste gate opens.

Weld on turbo housing? Are both turbo chargers working properly, creating boost?

jenyus425

thanks for your response! okay ill get down there today and see if i can move the rods by hand or not. so you're saying that maybe i can tighten up that nut and get my self a little more boost? if the wastegate is shot id assume that id have to rebuild the turbo, which would require yanking the motor, right?

i believe theyre both working correctly, but again i have almost no boost. it was a small weld and id assume that if it was leaking id have black soot around the weld.

Sgt G

On the wastegate, if the rod leading into it is threaded with a locking nut to hold its position, u can sometimes loosen that nut, turn in the rod (shortening it) like 2 fuels turns to creat more boost. Effectively what you'd be doing is adding stiffness/tension to the wastegate spring, requiring more boost pressure before it opens. Each 1lb of boost increase is worth roughly 5 hp lol.

If the wastegate is shot, it's the only part requiring replacement; no need to replace entire turbocharger if just the wastegate is bad. And since you mentioned it, if the wastegate does require replacement perhaps its a great time to replace it with a model that has a stiffer spring, that holds more boost and builds more power.

With almost no boost, there can be a lot of things going one, not just turbo related.