What can cause a 91 cherokee to run rich?

[Erik B]

I've noticed that even after i have my jeep up to normal operating temp (190-210F) that i can still smell a lot of gas burning. What are the things i can check out that could make it do this?

[PaulJ]

Dead oxygen sensor or a MAP sensor problem would be the primary reason for a renix 4.0. Probably the same for yours.