Mustang Killer

iTrader: (2)

Hey everyone, I just started noticing that my car shutter a bit under throttle. It does fine at red lights and under heavy acceleration, but under 15-25% throttle the steering wheel vibrates. I'm kind of confused as to what could be causing this. I just had the transmission rebuilt a couple of weeks ago and when I had them check it out they said that the transmission wasn't at fault. So I was wondering if anyone had any idea as to what could be the problem. Motor mounts possibly?

Mustang Killer

iTrader: (2)

Anyone? Also, my engine is throwing an SES light for a catalyst deficiency in bank 1, but I highly doubt that's what's causing it.