# Jeep Cherokee O2 Sensor Light **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** cherokee, sensors, jeep\ **Created:** [January 20, 2011, 5:04pm UTC](https://community.cartalk.com/t/jeep-cherokee-o2-sensor-light/60210 "2011-01-20T17:04:23Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![nagosnell](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nagosnell](https://community.cartalk.com/u/nagosnell)\ **Post date:** [January 20, 2011, 5:04pm UTC](https://community.cartalk.com/t/jeep-cherokee-o2-sensor-light/60210/1 "2011-01-20T17:04:23Z")
My Cherokee (4 wheel drive with the 4.0 liter I-6 and 105,000 miles) has a continuous problem with the O2 sensors. Years ago, the wiring was damaged on the rear sensor after my wife?s Labrador tried to eat it (tripping the check engine light). I beat the dog, replaced that sensor and reset the light. Months later, the check engine light came on again with an O2 code for the front sensor. I replaced the sensor and reset the light again. Months later I got another O2 code for the back sensor again. Thinking that I may have originally bought a bad sensor, I replaced that sensor and, months later, the check engine light came on again indicating an O2 sensor. Since then, I?ve looked for other problems that may be causing this. I replaced the intake/exhaust gasket thinking that it may have been sucking in cold air and causing the problem. I checked the fuel pressure and ignition; both appear to be in good condition. I recently replaced both sensors with new Bosch units and reset the light. It stayed out for a day and returned. Also, throughout this time, the truck will stumble at low rpm’s?usually after running and sitting for a few hours. It sounds like it is backfiring through the air intake when it does this. If I push the gas more, the truck accelerates fine and the stumbling goes away. Any ideas about what could be causing this? The truck has a slightly larger, aftermarket catalytic converter and a freer flowing muffler. I?ve tried to rule this out because the truck ran fine for nearly a year after installing this. It all started with the damaged wiring. Please help me get this truck running right or I will set it on fire and push it off a cliff. ---
**Author:** ![Bladecutter](https://avatars.discourse-cdn.com/v4/letter/b/aeb1de/32.png) [@Bladecutter](https://community.cartalk.com/u/Bladecutter)\ **Post date:** [January 20, 2011, 8:56pm UTC](https://community.cartalk.com/t/jeep-cherokee-o2-sensor-light/60210/2 "2011-01-20T20:56:59Z")
The car is upset that you beat the dog. If you apologize to the dog, and take the car to a shop to have the O2 sensor wiring checked, the car might forgive you, and stop having issues in the future. The problem could be from a related part of the fueling system, like the Mass Air Flow Sensor. If its getting lazy in its old age, it might not be sending a proper signal to the ecu, that then sends too little fuel while the engine is idling. You might want to have that examined. BC. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [January 20, 2011, 9:11pm UTC](https://community.cartalk.com/t/jeep-cherokee-o2-sensor-light/60210/3 "2011-01-20T21:11:57Z")
Find someone who knows how to troubleshoot with a multimeter and oscilloscope. Someone who can look at the signals coming from the O2 sensors and make a few resistance/continuity checks.