Hi all I need some help... K so I bought a 88 jeep Cherokee L6 4.0L 217k miles for like $800, so I knew going in that there would prob be problems.

On that note it was running pretty alright except I had to do a basic tune up, change some misc. parts and replace the cat back in Dec. A month ago I was headed to get groceries at about 45mph and the back right seat started smoking so yea that one mystery. There is a crack in the muffler and the exhaust runs right under neath that seat so maybe it heated up the body somehow an the glue keeping the carpet caught fire?

Main prob: Now when I start it it's running SUPER rich, like I can see and smell the gas fumes coming off the jeep. And when I try and drive it it tops out at around 20mph! I've seen a lot of "replace the o2 sensor" related topics but I would really like more input.. Please help

 

O2 sensor doesn't do much until the motor is up to operating temp. Do you have a leaking injector?
What happens when you try to accelerate above 20mph?

Oh...the rear seat smoke thing...are your floors missing under the seat? Not all that uncommon, they rust away. May well be the backing under the carpet getting hot. Mine were sagging through the rust hole, literally an inch away from the cat until I fixed the floors. That can't be good.

 

Yea my step dad replaced the injectors well actually I think he just cleaned them... And honestly I'm pretty sure he F'd it up cause he was forcing parts and it was all bad... I guess maybe that could be the prob... And nothing happens past 20... No excessive rev nothing just it won't go :/