I have a 94 chev 1500 with 350 and auto transmission. I experience a significant loss of power after the accelerator is pushed passed the kickdown stage, more than half throttle. I replaced plugs and wires and that didn't seem to make a difference. The air filter is new and the catylitic is new as of last year. I thought it was a tank of bad gas, but doesn't seem to be the case. One thing that is really strange though is that the tach jumps around all over the place, when the throttle is pressed halfway down. The tach bounces around back and forth a couple of hundred rpm, but doesn't seem to be mimicking the true engine rpm. Both problems started at about the same time.