Just put in a new exhaust system in the 86. BBk Headers, BBk H-pipe with magna flow cat back. When i accelerate there seems to be a slight hesitation before it kicks in and there seems to be a lot of vibration in the shifter.

What could be causing this????

i put a used set of O2 sensors in, could this possibly be the problem??

 

For the hesitation it could be your right pipe is too close to the fuel line above the rearend, causing the fuel to boil, the vibration may be due to the exh. resting on the frame somewhere, unless you loosened a mount or something.

 

my car dose the same thing now 2, its not that bad tho... and mine dose it once i start the car. it drops like 100 rpms and them revs