MoniqueTriana

I have a 95 Cherokee 2WD 4.0 6L. It is buringing rich, I have changed spark plugs, cap & rotor, all hoses. (Some were bad and cracked) I'm thinking that maybe I need to replace the O2 sensor, if not just for a little extra just in case what I did doesn't do it. Is there 1 or 2 sensors on this particular Jeep, and are they hard to change? I will be doing it myself. I'm not a master mechanic, but I can hold my own.
Thanks for any reply.... This is driving my Nuts!

00jeepXJ

There should be at least two on the jeep depending on where it is from. They are not to bad just a major pain because of rusting / baking themselves into the pipe. Disconnect the sensor before you start to remove it. Might want to have the special socket or open end wrench on hand, you can rent them from your local parts store usually. Hopefully if i forgot something another member can add it in.

tjwalker

95 is OBDI so it should only have one oxygen sensor. Replace it if there is any question as they have a finite lifespan of between 100k-150k, depending on engine efficiency. Do yourself a favor and buy NGK for this sensor as it is the brand of sensor that your XJ came with off the factory line. You can find NGK sensors available from many retail outlets or online. Never, ever, ever use no-name engine management sensors, including much of the crap floating around on ebay. Only order from ebay if it is a verified name brand.

How do you know it is burning rich? Did you check the spark plugs? That is one of the better indicators. If it truly is running rich, here are some things to verify.

1. Test fuel pressure. For a 95, you should have 31 psi at idle. Then disconnect the vacuum line for the fuel pressure regulator and the pressure should jump to approximately 39 psi. Be sure that the vacuum line is pulling good vacuum and that it is not wet with raw fuel, which would indicate a ruptured fuel pressure regulator which can make for a very rich mixture.

2. Test your MAP sensor, which is directly involved with fuel/air ratio. Testing procedure is in any service manual. This sensor also has a vacuum line leading into it; so be sure that vacuum line is in good shape and pulling good vacuum.

Good luck and keep us updated!