I had to replace a o2 sensor on the passenger side upstream. because that was why i was running lean. they cleared the code when we put the new one in. drove aroundn then the light came back on. The guy i kno a monroe muff. i know really well went out to my car and did some tests for me. he said that is has to be something w/ timing. but he cant change it there i would have to go to ford to reset my timing becuz thats why im runnin lean and getting some back fire. yeh i know i need a tuner but dont have the money now just tryin to fix the problem. any help would be appreciated... thanks

 

If it's a stock motor, the timing shouldn't be off. Sounds more like a sensor issue still.
What code was it giving?

 

It might not always be your o2 sensor. If you have any mechanical guru's near you have then check everything connected to it that might effect it. From wiring to the MAF. Checking everywhere else might save you $70 for the sensor. I might be wrong but is the code your throwing P0174? and are you also throwing P0171? If so, clean your MAF. Had the same problem myself.

If thats not it, could it be P1151 - Upstream Heated O2 Sensor - Sensor indicates lean - Bank 2? (Yes, I have a copy of all the codes sitting infront of me.)

That might help you too lilroush if you have advice for him.

 

the code is P0155 bank 2 sensor 1... the one i replaced twice because i thought the first one was faulty. WTF rar this makes me angry... but its not running lean or rich but still getting that little back fire and seems that my gas mileage has gone down also. and performance seemed to drop also

 

Have an exhaust leak at the header?

 

Just had the headers rebolted about a couple weeks ago, and doesnt sound like any leak driving, i know the guys over at ford and talked to them about it, i think im going to have them check it out. I mean it could be a little leak on that side but im not hearing at all

 

you mean P0156? I'm getting the same code. I had to "pay" to "pass" smog in order to register my car. Post up here when you find out what it is. The bf says it might be an electrical problem but we have not had the time to find out. Oh, and if its P0156, thats bank 2 sensor 2, downstream.

Oh, and he also said mt cat might be going bad. (I believe...) =x I certainly hope not!!

 

No the code is correct what i posted i just rechecked it, its P0155, bank 2 sensor 1 upstream. And if my cats going bad im going to be extremly pissed cuz that means money. But also a reason for long tubes :P

 

Hmmm... You know, I've noticed mustangs just don't like o2 sensors.... lmao

 

Yes no doubt...