So a little background first. I picked up my 92 Stealth TT yesterday. She is immaculate, bone stock aside from a stage 2 clutch, 150000kms, pristine interior, beautiful bodywork, etc. She passed mechanical so I figured she was a steal.

HOWEVER, and this is a big however
...

She seems to have a bit of an issue between 2k and 3k rpm, and (according to my stock gauge) 0-9psi. Any time I step on it, no matter what gear I'm in and I'm between 2500 and 3500 RPMs, and as long as I'm generating under 9psi of boost, the car seems to hesitate. And I don't mean it loses power - I mean it's a full-on stuttering, as though my wheels are locking up or my clutch is suddenly engaging extremely quickly over and over again.

Now I've done some searching and the common issue was the ECS sending faulty signals to the ECU (I had the dreaded flashing tour/sport light), so I unplugged it and the stuttering still occurs. Other than the physical feeling and lack of power, the car idles fine and I don't hear any weird noises. I was thinking it could be vacuum leak, but it wouldn't make sense that the issue would disappear after making MORE boost. Then I thought maybe a wheel speed sensor was off and it would lock up the wheels thinking they were losing control (that's almost what it feels like, like when your RPMs are too low and you let your clutch out).

It's not a huge issue, because other than that the car runs fine. But I would like to be able to step on it without that hesitation. Does anyone have any ideas as to what it could be?