California vs Federal emissions
 

I’m swapping my 3.9 which is California emissions for a 5.9 which is federal emissions in my 03 dakota. Will this be a problem? do i get a california or federal ECU, wiring harness etc. If anyone can help me that would be greatly appreciated

You are going to have to set it up with the california emissions..... So likely two cats, four O2 sensors, and heaven only knows what else.....

The 5.9 is going into a california emissions vehicle so it already has all of that, i was just wondering if i’d have to change anything because the engine is from a federal emissions vehicle

Now, I am not 100% sure on this... but.... If the down pipes from the 3.9 (which is where I assume the cats are) line up with the 5.9 exhaust manifolds...... I think you can just add the two additional injector circuits to the existing wiring, extend any wiring that won't reach where it needs to be, and have the PCM flashed with the 5.9 cali emissions tune, and you *should* be all set. I don't think anything externally on the motor was different, but, I haven't seen one either. Does your 3.9 have EGR? An AIR pump?

I’m not sure if i have one, i already pulled the 3.9. but I do have a 03 durango 5.9 pcm but it is federal emissions, you think that can be tuned for california emissions?

I can give you a definite 'probably'. :D So far as I know, the only difference between the ECM's is the programming. All the pinouts are pretty much the same. For Cali emissions, I think there are just more O2 sensors to pay attention to. (and not to neglect the extra cat?)

I recently moved to Cali with my 3.9 2001. I had to pass an emissions test that was administered by a lone employee at a small shop near the dmv. He performed a brief visual inspection and ran the truck on rollers (not sure why) and passed me. The dmv also did a visual inspection of the engine bay but mostly looked for the CA compliance stickers and took down that info. I don’t think either of the inspectors would have known or cared if it was the original engine. They certainly didn’t ask.

Hope this helps.

"technically" the computer will tell them what engine the VIN indicates, and if they are smarter than a bag of rocks, they'll see the engine has been changed.