hi, my 2000 s4 b5 loses power in rain and make loud exhaust sounds... It has only happened to me twice and both times in huge down pours- doesnt do it in light rain, which makes me think something is happening under the car where lots of splashing is hitting turbos or exhaust (i have APR full exhaust)..

Has anyone else experienced this? Its really annoying because all the sudden my car sounds like it has a hole in the muffler and loses some power...

Could water be getting in the turbo? but wouldnt that basically shut my engine down once the boost shoots a bit of water into the intake?

 

wierd, not a clue. maybe your ecu is getting moisture into it causing your engine to run poorly making it sound louder than normal

 

Maybe the rain was a coincidence, it wouldn't make any sense that it would be louder.. unless you have misfiring cylinders, but even then it wouldn't really be louder.

 

do you have darintake? maybe water is splashing up into the vents in you wheel liner n getting into the hole/s in you intake box?

 

Likely you have a bad coilpack or ICM. Any CEL?

 

Chances are your Intake if its an aftermarket piece may be picking up water if you accelerate dramatically near standing water... used to happen to my buddy's turbo car all the time.... the coldest air you can get to your motor is closest to the front wheel well normally. if your peice is based there its likely, If not no idea.. hope it helps.

Jason