Daviddrivesbetterthanyou

I have both p0053 and p0059 (o2 heater resistance codes) on my 2010 gt. I replaced both upstream o2 sensors and still have the codes. At first the codes would come and go, and now they're just always on. Also while this was happening my ac clutch would kick it on and off when I turned the ac on (blow cold air when it wants to) and now it just doesn't blow cold at all unless I jump the ac clutch relay. I had also recharged the ac and it still doesn't turn on when its suppose to. Can these 2 be related?? Any ideas on how to get rid of the o2 codes? I took my car to get painted for a week and when I got it back I drove it for an hour and the ac worked fine and my codes went away. Then 2 days later codes are back and ac isn't working again. Help pleasee

Phoenixs1234

Did you find a solution to your problem with the p0053 and p0059 codes and Ac problem?
I have a 2010 Mustang Gt and I am having the exact same problem you have.

imp

These codes are often used by Ford to alert it's Technicians to Cat Converter trouble. Especially found on high-mileage cars. I fought with heater-resistance codes a long time, replaced O2 sensors, even installed completely new wiring to them, until I learned the downstream sensors, used to monitor Cat function, are used as I describe.

Check the O2 sensor heater resistance first, using an Ohmmeter. Should be on the order of 10 Ohms, infinite Ohms to ground, of course. Best done with the sensor disconnected. The wire colors will tell you which two are the heater connection. If they're OK, you likely have Cat problems.

Jagpreet Singh

hey ,I have the same problem , have p0053,p0059 codes ,did replaced my o2 sensors but the engine light pops up back showing the same codes again .same thing with a/c too ,as was happening with you same here, can you plz help me how did you fixed that problem in your mustang
thanks

Phoenixs1234

On my car it ended up being the pcm. I sent it in to be checked and they found some weak solder points and it was losing ground.
They fixed the solder points and eerything works like new again.

Jagpreet Singh

thanks for your help ,I got my pcm checked at ford and it was bad ,got a refurbished pcm online and swap it into my mustang and everything started working like new , engine lights and codes are gone and a/c is working like new , I visited like lots of shops, spend lots of money but none of the shops had ever thought about checking pcm ,its all good now , thank you very much , I appreciate it

Phoenixs1234

I am glad I helped somebody. Like you I had gone to several shops and nobody could find the problem until I found the
right person and he fixed it right away.

imp

Same problem, I replaced the PCM, same problem. HO2S Heater Resistance 1-2; HO2S Heater Resistance 2-2. It's said by some that spacers which set the downstream sensors out of the direct gas stream can get rid of the CEL. Tomorrow, I'm installing them. Final analysis: replace cats, if need be.