what about a dohc ecu instead of a sohc ecu can I just switch them out someopne did it I was just curious...???

 

Why you would want to?

edit: But to answer your question, yes you can. However, just make sure that it is the same year as your car (i.e. a 95 in a 95, 96 in 96 or 97-99 in a 97-99)

 

Works fine, but the idle on a mostly stock regular SOHC is significantly richer. WOT is a little richer. Timing advance is better though. this is comparing the Mopar SOHC vs. Mopar DOHC though... The regular DOHC PCM would run even richer than the Mopar DOHC with less timing advance. Unless your SOHC has some serious airflow improvements (including bigger cam), you aren't going to get much from a stock DOHC PCM, and it might even hurt performance.

But if you're just looking to replace one to get home and the DOHC is cheap and nearby, it'sll work as long as the years match up, like Nick said.

best of luck!

 

I heard they are way better for an upgrade

 

What upgrade? The PCM's are programmed to run a particular engine. The DOHC flows much more air than the SOHC and has a lower compression ratio for starters. The valve timing events are very different as well. So the DOHC PCM is programmed for those parameters. If you stick a DOHC PCM on a SOHC engine, it will run fine on the freeway and most of your in town trips because it'll be in closed loop and the O2 sensor is running the show. At WOT (where you want power), the PCM uses a default fuel map. That map is rich even for the DOHC, so on the SOHC you're going to be running rich enough to actually hurt power. Using the Mopar DOHC PCM on the SOHC isn't quite as bad, but it wouldn't hurt to have some sort of fuel computer to help out.

 

would it work if your turbo'in the neon? runnin richer on wot, n all.

 

but wont it hurt the overall performance with the displacement being different?

 

I you're turbo, then the advanced timing is going to be the problem. It's not that big of a problem, and easily fixed with an aftermarket timing retard unit. Then again, fuel can be fixed several different ways with the stock SOHC PCM... Heck, for the money you spend on a timing retard unit and fuel computer, you could have a fully assembled Megasquirt and a wideband O2 unit...