Which Performance Chip do you have?

[Tyler Townsley]

Originally Posted by blackjack

i bought this improved calibration after reading mark haybeck`s site...my car`s 1-4 shift was disabled after installing the new calibration.as mark said it would..you can read the results on mark`s site under calibration for 1990..imo,its the best bang for the buck,for a stocker....mark also said 10%more torque because of more consistent underhood temperature,although i never mentionned the fans...jmo,anyway
blackjack

The stock calibration AYBK does not do anything about the 1 4 shift and the fans. Marc calibration which he calls AYBKG makes those changes and provides some other performance enhancments based on his experience in tuning the LT5.

So buying a AYBK chip/calibration from a dealer will NOT eliminate the skip shift. Marcs calibration is an excellent choice.

Tyler