Jeepcreep6

It hasn' been driven often the past year, just up and down my property to get wood, I just bought it from a man who has all receipts of what he's maintained on it. The exhaust was redone 2 years ago. No black smoke comes out of the pipe, but there' a bit of a smell. Anything I can do to fix it?

VoluntaryXJ

What does it smell like?

firebane

Its an exhaust it will always smell. Its what it smells like you need to worry about.

tjwalker

If it is running well and if there is no check engine light (no codes), then unless you have a "sweet" smell from the exhaust and you are having to add coolant, I don't see any need to worry.

It may help to just take it on a long highway drive with a bottle of BG44K or Techron fuel system additive in the gas tank, but other than that....just drive it.

Jeepcreep6

There is a “maint req” light on, I turned the key to get a code and the code came out as 12. I think I need a new oxygen sensor to turn the maint req light off, no?

Jeepcreep6

it doesn’t smell sweet, just smells like exhaust . I guess it is a 91 , not brand new

IJM

As someone else suggested, dump in a can of fuel system cleaner and give it a good flogging on the highway. Don't be shy with the loud pedal.

fb97xj1

Does it have a catalytic convertor? If not, the exhaust will smell like, well, exhaust. It can be relatively mild, or it can be quite potent. Depends on the air/fuel ratio. If it makes your eyes water, its running stupid rich. Some drivers are super sensitive when it comes to tailpipe emissions. If you are worried that something is wrong with the vehicle, check the fuel pressure. If its within spec, dont worry about it. Also, a faulty oxygen sensor can make trouble as well as the PCM uses that to keep the air/fuel ratio within spec. When the oxygen sensor goes bad, the air/fuel ratio will be out of spec. Running rich, for example. Another sign that something is wrong is if the exhaust smells like rotten eggs. If so, the catalytic convertor needs to be replaced. If it needs to be replaced, you need to find out why. Too much fuel for example will do it.

Check the fuel pressure. Give it a tuneup. Add a bottle of injection cleaner and take it out on the highway. Let it warm up first before you go speed racer on it.

As for the maint light, thats for the oxygen sensor. Its on a timer. Once it reaches a certain mileage the light comes on to let you know/remind you that the oxygen sensor should be replaced. It doesnt mean the sensor is bad. Look for a clear plastic box under the drivers side of the dash. Thats the timer, IIRC. Unplug it and forget it was ever there. Or pull the cluster and remove the bulb. Either way, no light.

JL89

How's your gas mileage? Worse lately? If so, could be vacuum lines.

Jeepcreep6

I just bought it, and i know jeeps aren't the most fuel efficient vehicles, but it does eat up gas quite fast