Replaced my o2 (only have one, pretty sure its supposed to be that way on a 93 sport 4.0) as title says, no cel but was getting crappy mileage so hoping this helps. My question is, should I reset the ecu to allow for maximum benefits? Or would that not effect anything positively or negatively?

 

Anybody have an opinion on this?

 

ecm will relearn itself when was the last tune up first suspect in bad gas mileage...

 

I'm sure it wouldn't hurt to reset it by unplugging the battery for a min and plugging it back in.

 

Cap, rotor, plugs, and wires all done together about 5-8k ago. Oil and oil/air filter about 500 miles ago also cleaned ccv and several other vacuum lines when I did the valve cover gasket at that time. O2 about 20 miles now. Not sure what more I can do to possibly improve it. I understand it wont be great with 32x11.5 mudders with stock 3.55 gears but it should be better than 12 mpg