Hey guys how's it going.
I've got a 2003 wrx and I just put the Cobb 3" turboback exhaust on a few weeks ago. Before I put the exhaust on I was getting a tiny bit of boost creep(I think that's what it's called). It would over boost to about 13.5 then come back to 10 and stay there, which is where it usually is. After I put the exhaust on it got a little worse, over boosting to 15, dropping to 7, then going back to 10. The other night I noticed that the boost is starting to fluctuate really bad. Mostly happens in 4th and 5th gear at wot and in 2nd and 3rd if I'm at 3k rpm and then go wot. It will over boost to 15, drop to 7, then bounce between 7 and 13 all the way to redline. Yesterday the car started to not go above 5 psi in 1st gear.
I've looked at all my hoses and they are all fine as far as I can see. I took it to a mechanic and they blamed it on my gauge, but I disagree because I can feel the boost going up and down. I haven't been able to get a firm answer from anyone, but so far the things that have been suggested are the wastegate, the bpv, or maybe a tune.
I plan to get the car tuned soon on a dyno but I wanted to make sure I fixed this problem first. I will be getting a new digital boost gauge soon so I can make sure that it's not the gauge, but again I don't think that's the problem.
The only mods on the car is the turboback and a drop in filter
Any help would be greatly appreciated, so far I haven't been able to figure anything out, even from my Subaru mechanic.