My 2002 ZX5 is surging under normal acceleration, not hard accel. Almost like someone is out back pushing me. It's a 2.0 DOHC with a A/T, but I know for sure the trans is not the issue because I had the trans replaced with a factory new one about 1500 miles ago. It also did this before the trans swap. Could this be an EGR or maybe TPS issue? Believe it or not, I've had it since new, it has 165,000 miles on it and has never given much trouble, other than one bad tranny. Any guesses?