Emiss maint light

[starkizer]

If memory serves, the emission maintenance light comes on due to the timer box thing under the steering wheel. At least that's how it is on the Cherokee. Am I right to assume its just that and nothing major. It's just telling me its time to check the o2 sensors. Don't we only have one o2 on the down side? Hope I'm right but lay it on me if not. And am I right that ill be hard pressed to find someone that van reset the code. Or..... We have the renix system that can't be reset and I need to junk that box. I really don't want to do that. Not because its hard (its really easy) bit because I'm a perfectionist and don't want parts missing, even useless parts. Any suggestions?

[MJRemi]

You can disconnect the box and save it or buy a new one if you want to keep it as part of your 'from the factory' goals. I think teamcherokee sells them but as you already know, these emission timers serve no real purpose.

[johnnyc]

I just took the bulb out of the cluster.

[Eagle]

It is not a reminder to "check" the O2 sensor, it is a reminder to CHANGE (replace) the O2 sensor. There are posts on the Internet about resetting the timer but, like many other people, I either unplug it or remove the bulb from the cluster. Change the O2 sensor every 80,000 miles (IMHO, multiples of 75,000 are easier to remember).

[starkizer]

So being that I drive less than 5k miles in a years time and have no idea if the o2 sensor has ever been changed ever should I change it now? Will I notice problems if the sensor is bad? I found a new timer from the local dealer but I don't know if my from the factory goal is worth 60 bucks when it would take me 30 seconds to disconnect the thing.

[Eagle]

So being that I drive less than 5k miles in a years time and have no idea if the o2 sensor has ever been changed ever should I change it now? Will I notice problems if the sensor is bad? I found a new timer from the local dealer but I don't know if my from the factory goal is worth 60 bucks when it would take me 30 seconds to disconnect the thing.

Result of a bad O2 sensor is a rich mix, backfiring, and destruction of the catalytic converter (either from explosive backfire, or just working too hard to catalyze the extra unburned hydrocarbons making their way downstream). In your case, I would change it and then forget it.

[starkizer]

Well its not back firing or buring rich or lean or anything. I disconnected the thing and it shut off. :( I didn't think the Comanche had a cadilidic converter? (sorry if thats spelled wrong, I'm tired) At least not in 89? I could be wrong but I don't remember seeing one under there. I remember thinking it was odd it didn't have one............ oooooooorrrrrrrrrrrr both trucks ive had, someone has yanked them off?

[Eagle]

They ALL had catalytic converters from the factory. If yours don't have them, somebody was cheatin'.

[starkizer]

Ok so I'm about to make a fool of myself. I should be able to see the thing somewhere before the muffler on the exhaust right. I'm gonna have to investigate now.

[carnuck]

My factory Renix manual had a section that showed using a matchstick to reset it.

[starkizer]

They ALL had catalytic converters from the factory. If yours don't have them, somebody was cheatin'.

 

Try as I might, I don't see a cat anywhere on either of my MJ's

[carnuck]

Diesel? ;)

[starkizer]

nope neither one of them is a diesel maybe I'm just blind. had a mechanic buddy look at mine and he said it wasn't there either. it doesn't look like anything is been cut off or anything so I don't know.

[shelbyluvv]

Take some pics of your exhaust. It was replaced by a new head pipe by a PO. All MJs came with cats. (except diesels)