hodge9386

has anybody ever swapped a 04 pcm into a 99-00 car? i have the pin outs for both pcms but i havnt had a chance to set down and compare them yet. basically i would need the pcm, connectors, move the wires that need to be moved if any and some tuning changes correct? or is it just not gonna work?

tblu92

WHY ?? your stock 99 ECM is plenty capable of approx 500 Crank HP---Typically to go beyond 500 Crank HP would mean you have added boost----
However there are other tuning options using boost other than an ECM swap A tuner can convert your stock tune to a "speed density tune" or a "semi open loop tune" both will accommodate over 500 crank HP
There is NO advantage to updating to a later model ECM unless you are over maybe 500 crank HP ( this would cover all heads-cam header engines) and up to a boosted engine with about 6-7 PSI boost

hodge9386

i am making 460 wheel so i am already over 500 crank but that isnt is reason i want to do it, you can make 1000hp on a stock pcm if you want. I am wanting to do flex fuel and i will need to swap to a p59 pcm to do it. from what i have gathered since posting this is it is plug and play. i would also get the advantage of a faster pcm with more tuning options.

tblu92

Ok then if you say now you anticipate using E85 fuel then of course you would need an ECM that is flex fuel compatible maybe 03 0r 04 a least

NemesisC5

Is there a vendor that offers an 03 or 04 pcm with adapter harness for 99?

K-Spaz

I think they just re-pin the existing harness. I can't recall where but somewhere in the last couple days I remember seeing someone who does this. Might have been on ls1tech dot com. If I can find it I'll post it.