68 RS

I hope you guys have some ideas for me.

This is what I have...
88' Formula Firebird 305 TPI / 5 spd.
Just did a tune up, plugs, wires, cap, rotor...Had intermittent codes 33, 34, 44, 45.

Car has a rebuilt motor w/ approx. 65,000 on motor. Exhaust was replaced with complete 3" from the Y-pipe to the mufflers and 2- 2 1/5" out the back. Bosch MAF (probably stock) nothing special that I could find on the rest of the car.

Here's my ? When the SES light is off the motor will not run above 4,500 rpm's. It will but there is no more to be had at that point and it sounds like it is running out of fuel and air. When the SES light is on from one of the codes mentioned above the cars will run right up and through 6,000 rpms and be pulling all the way through. (read no hesitation)

What are some possible solutions that I may be overlooking. The O2 sensor reads the right voltage at idle. This car isn't my hot rod but does a fine job on daily excursions and getting it to run tops would be greatly appreciated.

...Ron