recently the cel came on and had it read at autozone and code is po133. my cheap manual says it is "upstream heated o2 sensor circuit slow response (bank 1 )" what does this tell me?

i was on my way to dealer this am and the damn light went out, so i figured i'd give it a few days to see if it comes back on. can you give me some insight into this problem and or fix if needed???

THANKS...

 

They should still be able to pull the code.

 

The upstream O2 sensors get the brunt of the contaminents, so they are the most likely to get coated with garbage. Your best bet is to test the output voltage of both of your upstream O2 sensors. Having a worn out O2 sensor is not uncommon on a truck with over 50K miles.

These are considered by some to be maintenance items. Some people feel like changing them affords a better level of service from the engine. My personal feeling are that unless they are out of tolerance, then they are working correctly.

Go ahead and change the faulty sensor. If I were to do it, I'd replace both upstream sensors to avoid hassle in the near future.

 

Here are the probable causes;

Contaminated HO2S sensor.
Exhaust leaks.
Shorted or open wiring.
Improper fueling.
MAF sensor.
Deteriorating HO2S sensor.
Inlet air leaks.

Have you had any exhaust work done recently? Check for loose clamps or welds. Damaged wires on the O2 sensor. Look for loose clamps on the air inlet after the MAF sensor. Clean the MAF sensor and reset the PCM. If the code comes back change the front O2 sensor (s).

Regards

Jean Marc Chartier