ok so i startup tunerpro go to log idle blm's wait for the car to enter closed loop.. see that my idle blms are 150? LEAN! so i go to maf table 1 and increase fuel... go back out to the car and see the blms dropped.. so i take it around the block.. now its lean again? and it keeps doing this until you can smell gas standing behind the car..

theres no way its lean? o2 sensor voltage stays around 195/240mv at idle

 

Try a new O2 sensor. If you're in closed loop it should be rapidly cycling from .2 - .8 or so over and over. Sounds like your has gone south.....


- Vern

 

My new one (O2) may be doing the same thing. I have a cal BIN that worked really well 2 weeks ago. I fired the Jeep up today and my BLMs at idle were sitting around 116 with INTs of 120-125.
Bizarre...

 

Sounds like a poisioned O2 sensor, or a Bosch one.

Try another sensor. If you can just grab a handful for cheap at a junkyard, they'll do just fine. Just don't get a Bosch, they have the world's worst track record.

Personally, I consider it worth while to use heated ones.

 

Have you disconnected the battery so that it has to relearn since then? Other wise it makes no sense if you haven't changed anything. Have you done anything to it at all?