Ok so I have a 94 zj with the 5.2L. It has 224K and the motor was running great. Out of nowhere it started overheating immediately after starting. After looking things over I noticed that when I took off the radiator cap (when first started and the motor was cold) I was getting exhaust bubbling up from the radiator. Needless to say I had a bad head. I also found out after tearing it apart that I had leaking valve guide seals and was burning oil. I decided just switch the motor with a spare 5.2 I took out of a 96 zj that was totalled (damage was all in the rear end and nothing wrong with the motor) and had 140k on it. Everything was the same except for a few minor things like the temp sensors and such which I replaced with the parts from the original motor. The only big difference was that the 96 motor didn't have EGR setup. After switching motors everything runs fine and is working as it should with the exception of my check engine light is on due to the EGR not being there and none of the sensors are hooked up for it. Is this a problem? Or can it cause problems in the future not having the EGR?

 

The only issue is whether you're required to have all the original emissions equipment in place where you live, if/when you have emission testing done. Since the '96 engine never had it, it's not needed. Since the intake and heads (and some small other things), would have to be changed to add it, I'd run without it if possible. Just my opinion of course.

 

The only problem would be if you have smog inspections, other than that, no big deal.

 

We don't have emissions inspections here in my state so I guess I'm ok. Thanks guys. What do you think about changing the computer to the 96? Wouldn't that eliminate the check engine code since the 96 didn't have the EGR? It's not that important but the light is quite annoying. It was never on before lol.

 

The 96 ECM won't work in the 95, it's a completely different animal. 96 was the first year for OBDII, your 95 is OBDI. OBDII has more sensors required, like three more O2 sensors. I would atleast plug the EGR pressure transducer into the harness, it may keep the light from coming on even if the EGR valve isn't there.

 

For CA.
Do you know that next year all CA residents will have to wear pants with catalytic converter attached?

 

Update: I hooked up the EGR sensors even though no vacuums go to them and the check engine light went off! Thanks bustedback for the suggestion! Running great!