Originally Posted by Turd Nugget
Ok, so I pulled out the BCS, put it on a dc power supply, pulsed it a bunch of times and it seems to be working normally. I blew in one side and pulsed it and air came out the other without restriction. I cleaned it anyway with some iso and stuck it back in. This car is 100% stock yet, so maybe next weekend i'll put in the up/downpipes and while I'm at it I'll inspect the wastegate area for cracks and make sure it is shut all the way. I'll report back. Sorry to thread jack but it doesnt seem right to make a new one for the same problem.
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