Surging after power pipe installation

I just installed a UPR power pipe on my car. After installing it the car seems to surge at lower RPMs under load. It idles fine and will rev up fine when it's not being driven. It never did this before I in stalled the pipe.

Any suggestions?

Here's my combo:

92' LX
331 w/ tfs heads
gt-40 intake
s-trim (6lbs)
SCT MAF
UPR Power Pipe
SCT custom tune

Its most likley due to the increase in air flow. The MAF is probably pissed. Time for a retune.

Got an appointment setup with my tuner for this Tuesday :)