Hello fellow gearheads! Mine is a 95 grand laredo with the 4.0 six. The motor is a replacement with 50k on it. Above 1k rpm- she's smooth as silk. But below, thats another matter. It coughs & sputters, occassionally stalling at very low idle. but then it'll kick up a bit, & idle fine. The check engine light is always on- but that could mean anything. I'm a shadetreee gy, bt fgrd 'd tap into this resource 1st. Just looking for an idea on where to begin.

 

First thing you should do is take it to any parts store and pull the codes. That would give you some idea what to look for.

 

pull the throttle body and give it a good thorough cleaning... scrub the bugger good. Be sure to remove all sensors and the like before hand though. 4 10mm nuts and it comes off. You can reuse your old gasket if it's not torn otherwise most parts stores carry them for around a 1.
Also go through and take a look at all your connectors and make sure that they are all attached properly.

When cleaning your throttle body use carb and choke cleaner or something similar just not brake cleaner as it's really corrosive.