Im having a 0 boost issue on my aeb 1.8t. Under vacuum it runs perfect but the second i try to get into boost it shoots up to zero. The exhaust sounds boggy like its being choked and there is a whistle or whine noise which comes from under the hood. This will only happen under a heavy load. I replaced my k03 thinking the turbo was blown or a wastegate issue. The turbo i installed is a newly rebuilt k03 with 0 miles. I have also installed a n75 valve that i know works and still the same. I replaced the apr DV with a brand new forge 007 that i have and still the same.

2 week ago i did get code p0422 for the cat, but i cleared it to see if it would reappear and hasn't. Would a clogged cat or junk 02 sensor cause only high load problems? So to sum it up i have no CEL, runs great under vacuum, and sounds choked under WOT or high load. Thanks for the help guys

 

A clogged cat will cause the car to feel choked when putting the foot down, I would say it would be worse of at high load as more exhaust gases are running through, not sure however if this relates to zero boost.