I am nearing completing my v6 to lq9 swap. I have an 02 firebird and purchased a harness and pcm from a 98 ls1. I am about to do the modifications to the harness but something sticks in the back of my head about the 98pcm and forced induction. Seems like you cannot go more than 1 bar. I plan 20psi from my t88 on this fully forged motor so if anyone can let me know if I should use a different harness or pcm it would be greatly appreciated. I would hate to get the harness ready for the 98 pcm and find out its not a wise choice. And yes I know bs3 would be much better.

 

you can use the harness you bought and just re-pin it to work with 99-up pcm.

 

awesome that helps a ton. Thanks!

 

before you go modding the harness isnt the car with the v6 a 2002? if the car is a 98 then yes modd the marness and use the 02 pcm.
If you are using a 99+ car you are better off getting a 99+ harness it will interface with the car better.
Are the sensors you put on /came with the lq9 on the engine the 98 sensors or the 99+?
If they are the 99+ (temp on 98 is 3 wire, the oil pressure is 2 wire on 98) use a 99 harness.
PM me if you want to chat about it.
I have done the v6 to v8 swaps.

 

God that helps a ton. I have been just researching like crazy. I could always use help from someone who has done it. I will be assembling this summer. I am going to do a 03 harness for a silverado with an 02 camaro pcm. When its coming together I will shoot you a pm. Thanks!

 

God that helps a ton. I have been just researching like crazy. I could always use help from someone who has done it. I will be assembling this summer. I am going to do a 03 harness for a silverado with an 02 camaro pcm. When its coming together I will shoot you a pm. Thanks!

 

anytime.