throwing codes - O2?

[stangman16]

Just changed my oil and replaced the battery yesterday in my '99 Mustang GT. About 45 - 1hr of driving afterwards my CEL comes on, I get codes

P0136
P0141

Could this be related to the new battery? Or is it just time to replace some O2's? I'm at 99,350mi. I really don't want to buy the rear ones, I'd rather get a MIL eliminator till I can afford the Diablo tuner. Being that this said something about circuit fault, could this be more than just changing O2's and adding a MIL eliminator or not?

 

[chuck943]

both codes are for bank1(passenger) rear O2. These are circuit codes set for either open/shorted cicuit.These codes set when the PCM performs the HO2S monitor and checks O2's for current draw. These codes will set if current draw exceeds a calibrated limit or if they fall below a calibrated limit.
Make sure you don't have a loose connection and make sure harness isn't pinched anywhere. Check connector c106 also, it is a black 16 pin connector near ac accumulator near firewall passenger side.

 

[stangman16]

I'll check it out first chance I get, thanks. If the wires are good, should I just get MIL eliminators instead of buying a new rear O2?

 

[StangIt #1]

If the wires are good, should I just get MIL eliminators instead of buying a new rear O2?

I have Steeda MIL eliminators and still had to replace one of my rear O2's when it went bad. The computer was throwing codes, even with the MIL's. Just to test, I switched the rear O2's, and the codes switched from left bank to right bank. When I switched them back, the codes reverted to the originals. BTW, I bought 2 Bosch replacements and they both threw codes. I had to ultimately buy a Ford OEM ($$$, and manufactured by NGK) to remedy the problem.

 

[stangman16]

I have Steeda MIL eliminators and still had to replace one of my rear O2's when it went bad. The computer was throwing codes, even with the MIL's. Just to test, I switched the rear O2's, and the codes switched from left bank to right bank. When I switched them back, the codes reverted to the originals. BTW, I bought 2 Bosch replacements and they both threw codes. I had to ultimately buy a Ford OEM ($$$, and manufactured by NGK) to remedy the problem.

Dang, I was hoping that would fix it. How about if I save up and purchase a tuner and delete the rear O2's, would that do the trick? I know it'd probably help me out in my mpg as well.

 

[StangIt #1]

Dang, I was hoping that would fix it. How about if I save up and purchase a tuner and delete the rear O2's, would that do the trick? I know it'd probably help me out in my mpg as well.

I think most handheld tuners do have the ability to disable the rear O2's. The Steeda MIL's were simply a more feasible option for me (the only other real advantage to a tuner on a '98GT it timing advance); unfortunately, one of my rear O2's went bad within 2 weeks of removing the cats and installing the MIL's.

 

[hotmustang331]

Yes, turning the rear 02s off in a tune will do the trick. I dont even have rear 02 sensors anymore . Just unplugged them because my new X pipe didnt even have bungs for them haha...but since Tim turned the rears off, it didnt matter