MY 97 CHEROKEE ENGINE LIGHT CAME ON. WHEN I HAD IT TESTED IT SAID RUNNING TO RICH. It does idle rough. they daid it could be maf sensor or as easy as gas cap. I am only getting about half the gas mpg as i was. only about 100 miles per tank.

 

hmmmm, o2 maybe?

 

spark plugs?

 

crack in header

large enough to let air in to the exhaust making the o2 sensor tell the ecu to dump more fuel to balance out the air to fuel mix

 

thanks i took it to my buddy he said it was the o2 sensor, i will try to to fix it saturday. thank you..