My car: 02 WRX sedan Cobb catted downpipe stage 2 AP custom tune.

Ever since I got my car custom tuned it's been running stronger than ever. Until this weekend. I went up to about the 4-5K foot elevation to visit with friends. The temp dipped below 50. On the way home I noticed that when I hit full throttle, the boost (According to the AP) would go to 18.5 then down to 14, then back up to about 17.5, then back down, and up. This would go on until I let off the throttle. If I gradually went to full throttle it would not do this It would just hit full boost (about 16.5- 17lbs). So I got back down to sea level and reset my ECU. The car did the same thing. It wasn't until the next day that the problem seemed to almost be gone. However I did notice it a couple of times.

I had this problem before prior to going to stage 2, but it went away. I'm thinking it has something to do with the temp. But what do I know?

Has anyone had this problem? Do you think it's a mechanical issue?

Any ideas are welcome.

Thanks!

 

i want to know also

 

1st you need to check the vac lines/fittings that run from the FBC (factory boost controller), WG (waste gate) and turbo outlet to make sure everything is hooked up correctly and snug. If everything looks OK you need to disconnect the FBC, run a piece of vac line from the turbo outlet directly to the WG. If boost holds steady at around 7.5 psi you know the WG is functioning properly and the problem is elsewhere. Next try to get someone to lend you their FBC for an hour and see if the problem persists.

When this happened to my 02 Cobb stage 2 WRX it was just the vac lines so hopefully you luck out like I did.

BTW, the boost spike you are experiencing is not a good thing so if you can’t figure it out just run off WG pressure until you figure it out. If you keep running it like that you’re engine might go BOOM.

Good luck
Joe