These past 2 weeks I've been noticing a tank in my mileage. I usually go about 110-120 miles on a little over 8 gallons of gas, averaging between 13-15mpg usually. Last week, I went about 80 miles on a little over 8 gallons. This week, I'm noticing the same thing happening. The temperatures went up from 50s to 70s over the 2 weeks, would that make my mileage drop? I've been driving the same way to the same places I usually go. My jeep is a stock 4.0 auto with stock tire size. I'm thinkin my o2 sensor is startin to go. Is there a way to test it before I buy a new one? I have an 89, so I don't have a check engine light to tell me that it's time for a replacement.

 

Have u been using AC? Put in new plugs and get some O2s from rockauto.com you can get two for the price autozone sells one.

 

A/C don't work. haha. I put new plugs in recently, so those are fine. I'll check rockauto, thanks! Any particular brand? They usually have a few for a selection.

 

Ac bearings maybe catching? Any noises? Not sure on brands

 

No odd noises. A/C spins fine, just the lines are cut off from when I had the heater core replaced. Everything in the engine runs fine. Sounds like it should. My first thought was the A/C bearing not letting it spin properly. Its just been odd these past 2 weeks.

 

Get NTKs off rockauto.com

 

Thanks, I'll look into that tomorrow probably.