I don't mean to spam, but I the check engine light on my Comanche was on, and I think I just fixed it, so I figure I'd throw up a quick post for posterity in case anyone else faces the same issue down the line. I said '99 Cherokee in the title because my Comanche's has had a '99 Cherokee 4.0 put in, so the light relates to that engine.
Anyhue, I pulled the codes P0132 and P0135. Apparently, according to forum browsing, these codes relate to the front O2 sensor's heater, which has a fuse. So either a fuse is blown or the O2 sensor is bad. I started by checking the fuses, and sure enough, two of them looked all milky and blown. I replaced them, cleared the codes, and drove home. So far, so good, with no return of the check engine light.
Here are some pictures of what I replaced: http://postimage.org/gallery/14x4at9m/
Anyhue, I pulled the codes P0132 and P0135. Apparently, according to forum browsing, these codes relate to the front O2 sensor's heater, which has a fuse. So either a fuse is blown or the O2 sensor is bad. I started by checking the fuses, and sure enough, two of them looked all milky and blown. I replaced them, cleared the codes, and drove home. So far, so good, with no return of the check engine light.
Here are some pictures of what I replaced: http://postimage.org/gallery/14x4at9m/