I remember reading a thread here about a month ago were someone said that a 5.2 computer will run a 5.9 just as well, and they had dyno results to prove it.


If this is true, it would seem that the computers are tuned about the same. But I would think there would be some minor differences from one year to the next ?.

 

For the most part, once the engine gets into closed loop, there is zero difference between motors. O2 sensor makes adjustments. In open loop, the 5.2 PCM would run the 5.9 a little on the lean side in open loop, but, from the factory, they are programmed a little rich in any event. So, technically, sure, it will work. Is it the best solution? No. Not really.

 

^ so that means a 5.9 computer will run a 5.2 a little rich until it gets to temp?

 

Exactly.

 

Huh. That might explain some things