Rpms drop down to 200. What's the problem?

[-DSM2NR-]

Since I've installed my 2.5"-3" downpipe I've been having problems with the rpms dropping down to 200. This happens when I either race or drive the car hard. I've also noticed that my boost went up by 1 since I've installed the downpipe. It's at 16psi now on my stock T25. I've pretty the rpms drop since the boost is currently at 16psi but it should be at 15 max. I don't have a boost controller so I can't currently adjust the boost level. What should I do? Is this a big problem?

 

[larsenracing]

the boost went up because if the dp less restriction and all. as for the rpm drop could your plugs and wires need replacing.

 

[-DSM2NR-]

I doubt my plugs and wires need replacement. They were replaced before I put the downpipe on.