boost issues
 

Hi, i have a 99 wrx, when putting my foot flat to the floor, the boost flactuates between 6psi and 14psi at a smooth pattern. This happens through the rev range. Any ideas? thanks

Initially, check all vacuum and boost (cooler piping etc) lines for leaks.

I would take it to a workshop, may be airflow meter

Also check how the boost gauge is installed.

yer id say AFM or a vacuum line, mine did it when my AFM shat itself.

iv had the boost gauge installed for nearly a year, its only done this boost problem twice and last night. its always down the freeway having the foot flat at 3,000rpm and having it on boost it starts to do it. It's like it is only when its on boost for a long period of time..