My '91 318 Dakota was getting real bad gas mileage, and the power just wasn't there. I read on this forum that the o2 sensor was probably bad. Long story short, it failed emissions and I dropped it off at my friends shop.I was going camping and didn't have time.He said the o2 sensor was beyond bad!The computor was dumping full rich, and it had a vacuum line leak.I got it back all fixed. HOLY CRAP! The power is all back and I went from 124 miles per tank to 245 miles with 1/8 tank left!! [15 mpg] It accelerates with ease and just goes. I was driving 50/50 stop and go / highway when I got that many miles, and also accelerated pretty quick a few times, so it should be getting better if I drive nice. I feel like I got a new Dakota.

 

Cool, easy fix.