Hi,
I have a 95 Cherokee 4.0 6 2 wheel drive with some rich fuel burning issues. I had never had problems with emmisions in the past but am not passing emmisions. I have concluded that the fuel is burning rich, so I replaced all hoses (some were cracked) and replaced cap and rotor and plugs. It seemed to run better so I decided to take it back to emissions before replacing more costly items like the o2 sensor or fuel pressure regulator since I do not seem to have any sputtering, problems starting, high idling and it drives fine. I started it and let it run to get the cat hot, and noticed that I had some hard running while pressing the gas. I decided to check the plugs and the first one I pulled was hard to take out and cracked on the ceramic. All the others looked burn already (they have only been in and havent driven anywhere but it being on in the driveway and driven around neighborhood.) I see this is because rich fuel burning. Can anyone give me any ideas what could be the issue if I am not having any problems with idle, sputtering or performance.
Thanks everyone

 

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