ok last night under some hard acceleration on my 99 a4 1.8t my exhaust not suddenly got annoyingly loud. So i pulled over and tried to location the source of the noise and immediatly knew it was high allong the exhauset by the engine bay. it was dark out so i let it be as i cant fix it now

well i just went out and had a second look at it in better lighting and it looks like the downpipe is completly off of the turbo. im not even sure how it is suppose to stay on looks like its just pressed over the flange on the exhuast side of the turbo. but i dont know if there is some clip or whatever that i am missing

also if there would be any cheap upgrades i can do in the general area

 

also would like to note that when i give it a small amount of throttle i get a very nice high pitched whistle from the turbo but to much and then the annoying exhaust over powers it

 

that's the sound of a turbo spooling up

 

If you don't see studs sticking out, Then they most likely broke off and thats why its not connected any more. Also thats not your down pipe its your cat. Three studs are supposed to stick out of the turbo and the cat bolts to it. Check your turbo for any possible damage as that may be where your noise is coming from.

 

Sort of common for the welds on the cat flanges to crack. It's not the down pipe by the way, its the cat. It goes exhaust manifold->turbo->cat->down pipe

 

i think its more the weld for the cat to the flange. the bolts and flange is still connected to the turbo

but if its a common thing with the welds breaking then ill have to reweld it back on durring the week

 

correct me if im wrong, but i don't think its welded on man. if you unbolt the cat from the turbo, it should come off.

you should buy a new gasket and some bolts and tighten it back together.

 

you can buy a vmr test pipe for your a4 on ebay... they run about $80 and best part is you can sell your stock cat to your local scrap yard for $150+... so you actually make $$$ from this mod =)

 

u have the cat then the o2 sensor then a short section then the flange which bolts to the turbo

the flange is still on the turbo with all bolts just the flange isnt connected to the rest of the exhaust and its a clean straight gap so it looks like the rest is pressed on then welded.

 

Ok, yea I know what your talking about, But yea take the advice and just upgrade it, if you don't need to pass emissions test pipe it, if not just get a HFC.