I think i need to get new o2 sensors for my jeep, i go through a full tank of gas in 150 miles. lifted 4" with 32s. whats a good brand of o2 sensors for cherokees?

 

Bosch are good.

 

Mopar.......

 

will the o2 sensors really effect the mpg??

 

Yep! They regulate and and keep the fuel and air ratio efficient. Assuming their in good condition.

 

is there a way to verify if they are out or bad?? Would I have a CEL?

 

Not necessarily, the best way to tell is to unplug it. See if it runs better. The ecu is programmed to run at a certain level of air fuel ratio. So o2 sensor adjusts it accordingly, so if the o2 sensor goes out the system just goes back to it's original programming. It won't be as efficient but will at least run.