2001 Cherokee Sport 4.0L Inline 6
I recently replaced my catalytic converter with a direct OEM cat and have noticed over the past 3 weeks that I'm getting lower MPG. Is this normal or temporary? old cat - avg 215-220 city new cat - avg 185-190

Also, when I looked underneath, I noticed a dent in the exhaust pipe as it snakes from the point after the cat is bolted. Is the dent factory?

 

Yep. Lower mileage is standard.

It sucks, but you are saving the world. That's what I still am trying to convince myself of.

 

Did you disconnect the battery to dump the computer memory?

Pull the battery cable, turn the headlights on for about a minute.
Reconnect battery.

Drive the car easy for the first few miles.

No idea about the dent

 

The exhaust pipe dent is in there from the factory.

Get at least 3 calculated gas mileage readings before making any assumptions. Do the math. Miles driven divided by gallons consumed. This is the most accurate way of figuring out your mileage.

 

Need more info. If you're saying that you're getting 190 miles per TANK. You've got WAY more other problems than just the cat.

 

If I hit 190 miles on a 15 gallon fill up Im happy.

Mine is not stock however.

 

X2!!

Right now I'm averaging 310-340 per tank. As I've never let it run completely dry I'm sure I can squeeze a few more miles out of her. So if you're only getting 220 per tank I think you should start an investigation and see what else its eating your gas mileage before you tackle the new cat.

 

I've changed out everything except the cat. Still get 17 mpg

 

That's like 19-20 mpg. You must be driving down hill and with the wind to be getting that good in town! :0

 

It's not that hard to do. I routinely get 22+mpg out of my stock 97 4.0L 4x4 auto.

 

Not to bad for the hwy...I'm getting about 18 if I keep it under 65.

 

Um so 14 MPG city in a stock jeep is not normal...?

 

Yea I'm stock and getting like 13-14. I've just come to accept it as owning a jeep. I do have a heavy foot though (18 yrs old)