Called around to a few salvage yards and keep getting told there is no difference in the PCM's. So is the only difference in the flash programming?

I know the '99 runs a 2 wire knock sensor and high impedence injectors. But can I just reflash the '97-'98 to a '99 program??? (using the HP Tuners stuff)







"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"

yes the pcm is the same 97-99 , only the reflash and pin-out are different

if you search for the 97-98 swap to 99 , there should be info on swaping the 99 knock sensor

the stock 97-98 knock is in pin 33 , and 99 is in pin 32 and 34 , i got the pcm connectors at the junk yard so that i could add the extra wire into the pcm in my cav (ive still got some if you need 1)

and i added the 1 wire to the harness , ive got the part # for the connector end that plugs into the knock sensor at home

everything else is the same

ive done the swap in my 97 , and never had any problems

Cool I have all the pinout tables for '95-'01, I'm just going to use one of the leftover wires from the EGR and pin in to the 32 slot and move the 33-34 slot for the knock sensor. (thanks to Brian for the idea)

So are you running high impedence injectors in your '97?

I've got the '96 swapped out to a '98 , so now I'm just playing around before I button the car back up and start tuning.....





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"

nope , im running the 2.3 HO injectors , never had any issues

still trying to track down that black wire....... crazy.

This 98 vs 99 has come up a few times....... I could have sworn I've seen a different part number for the 99 ecm (compaired to the 97-98)....... but since I've made that claim, I havnt found anything on it.

From what EVERYTHING has said about High vs. Low impedance drivers/injectors...... you would assume there would be some different hardware between the two, to handle the different current demands.

I have flashed 97 and 98 ECM's with the 99 program, and kept the stock injectors w/o any problems.




SPD RCR Z - '02 Z24 420whp
SLO GOAT - '04 GTO 305whp
W41 BOI - '78 Buick Opel Isuzu W41 Swap

97-99 pcm's are the same , no matter what trans or engine , just the programs were different


mine still gets great milage the way it sits with the HO injectors , and 99 pcm