1990 cherokee problem

[forbyer]

4.0

Runs rich. Doesnt blow black smoke. I just replaced the coolant temp sensor and that didnt do anything. It also idles way to low. It idles at 300rpm and it should be a at 800. So anything would help. thanks

 

[jeepmauler]

Make sure youre cats not plugged...If you still have it.Check O2 as well