I recently did a top swap on my 97 Grand Prix GT. I'm using the 97 GTP PCM from the donor vehicle. I changed all the tables in the trans files to 97 GT factory data, but for some reason the GTP PCM still will not shift the trans from 2nd to 3rd and 3rd to 4th. Also, if I put the vehicle manually in 1st, it will still shift to 2nd. I would've just put the L67 engine data on my L36 PCM but I have the serial version of HP Tuner and my OSID is not supported as I have an early 97 Grand Prix. I've even gone to the extent of tracing wiring diagrams. I'm just lost and need some direction. Any help?