Two days ago i installed rk sport crank pullie and alternater pullie, along with those i put on a 2.5 inch y-pipe and a high flow cat from MacPerformance. I took the car out to drive it and i found out that when accelerating hard it it down shifts like normal but onece it gets to 60 when it use to shift, now it just keeps building the rpm. But this does not happen when accelerating normaly.
Does anyone have any suggestions on what could be wrong?(i took off the 52mm throttle body because i thought that would help and it did nothing). Do i need to reprogram the computer with having the under drive pullies?(i have and automatic trans) PLEASE SOMEONE HELP!!!!

 

The pullies won't effect the transmission. Maybe you hit the transmission linkage when you were installing the y-pipe and cat?

 

i was thinking because the puulies now spin faster when under hard accelerating the car does not get a chance to catch up with the new timeing, has anyone ever heard of people with auto trans haveing to reprogram after installing under drive pullies

 

Perhaps it has to do with the TPS on the new throttle body. The shift tables use throttle position as one of the inputs for determining shifts.

Maybe you got it out of whack and did not get it returned to the way it was. A scanner would help in determining if it is ok.

 

would a local mechanic have one of these scanners?

 

Yes.

 

ok after driving it awhile today i now know that it stuters to shift in to third from second when accelerating hard. from a dead stop it shifts fine from first to second, but not good from second to third. i don't know what the proiblem could be?