'92 cherokee. Last month I changed the O2 sensor, E3 plugs, exhaust, rugged ridge cold air intake, etc. I reset the computer, and I'm getting WORSE gas mileage.... Any ideas?

 

Are the plugs platinum? Platinum doesn't always mix well with the 4.0

 

Yeah, do you enjoy listening to your new exhaust???? Cause I'd bet your pushing down on the gas pedal so you can hear it as much as possible....

 

yea ditch the E3 plugs. Copper Champions are the best for the 4.0

 

x2 more vroom vroom less mpgs, and take the plugs back get champs

 

e3 plugs=holy pistons
get rid of them.

 

have you checked if any vacuum lines are disconnected? it could be pulling unmetered air causing the o2 to read erroneously

 

Thanks guys, I will ditch the plugs and see if that does help. I dont know about the vac lines though. I guess that means, i'll be in my happy place... shoulder deep in the engine bay!

 

just get some carb cleaner and spray it around the vac lines, if you hear the engine want to rev, you have a leak.

good luck

 

Give us some gas mileage numbers.

Need at least three samples.

Must be calculated. Miles driven divided by gallons consumed. Trying to extrapolate mileage by how many miles you get to a tank of gas isn't particularly accurate.

And I agree with the others on the E3. They are overhyped and for the 4.0, give you no advantage. Champion copper plugs properly gapped to .035, changed every 30k.