I tried searching for this but I couldn't seem to find anyone with the same problem. Here's the problem

- If I boost in 1st gear, when I shift to 2nd gear I get no boost. The vacuum/boost gauge just reads 0. However, after I shift into 2nd, if I let off the gas for a second or so and then step on it again, I get full boost and proper boost pattern.
- If I do NOT boost in 1st gear, I can shift into 2nd gear and mash the gas and get full boost and proper boost pattern.
- If I'm cruising in any other gear (2nd, 3rd, etc), I can mash the gas and get full boost and proper boost pattern.

Mods on my car are street ported motor, downpipe, catback exhaust, pettit hybrid twin turbos with boost pills removed in the wastegate lines, stock CPU. As the boost pills are removed, when I refer to full boost, I mean 7psi. Proper boost pattern for me would be something like 7-5-7.

Any ideas on what the problem is?

 

You have a leak associated with the vacuum chamber.

http://www.autosportracetech.com/RX-...leshooting.htm

 

or a one way check valve also associated with this as rynberg had pointed out