Originally Posted by greenplates
Ok so I have been through this same situation.
1. Replacing the stock BCS with a new one is always promising, they get old and worn out
2. Your vacuum lines dude? The ones year the turbo and the ones near the throttle body get old and cracked. THAT will cause boost fluctuation
3. Make sure your couplers on intercooler are tight
This takes less than 20 minutes, is free, and helps a lot
I took a close look at the vacuum lines, Impressively this car looks brand spanking new under the hood, all the hoses and lines even still have some shine to them, none of them feel hard at all. I had the intercooler off a few weeks ago when I seafoamed it and double checked all the couplers.
I looked at a handfull of these wrx's and as soon as I popped the hood on this one I was impressed at how clean it looked. Even the intercooler looks new, where as every other one I looked at has bent/corroded fins. After I bought the thing and put it up on jackstands to get a better look at everything I noticed overspray, the car was def repainted but I cannot find any signs of repaired dammage inside or out so maybe it was just hail dammage or something idk. I'm from wisconsin and its hard to find 10 yr old cars not rusted to ****, this one came from texas a year ago so that would explain why I suppose.