I started having the same problem around 80,000 and eventually had to replace the transmission. you really need to hook it up to a scanner to find out.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
bad fuel filter
Bad Struts
on the 4.0 jeep, if it cranks, but wont start, try replacing the crank sensor, located at the top rear of the engine, at the transmission
Yes.
There are several things that can cause heater problems in your 1998 Jeep Grain Cherokee. The most common cause of heater problems is low fluid in your cooling system.
Sounds like a brake wear indicator. If it changes while braking then it is. Recommend a brake inspection.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
most common cause, a vacuum leak.
your oil pump is bad
Just about all of the engine sensors could cause it to not run.
trash in your fuel filter