O2 sensor

**stern2192** · 03-26-2012, 02:47 PM

Hey guys I have a 2001 z28 ls1. My Check engine light flipped on when I was going heavy on the throttle. So I took it to the local auto parts store and had them run the codes. I got P0131 and P0151 which are O2 sensors codes, the guy would not clear the codes for me. Would it be alright if I disconnected the battery to reset the car to get the light to turn off, or should I replace the sensors I heard this is a common problem though, any input would be great, thanks!

**stern2192** · 03-26-2012, 02:55 PM

I also replaced three sensors about a month ago.

**pajeff02** · 03-26-2012, 05:44 PM

What brand sensors did you buy? Are you running LT's? If so, are you using extension harnesses?

The code was triggered by the PCM sending low voltage from both of your pre-cat sensors -- Bank 1 (left side) and Bank 2 (right side). It could be a faulty sensor, defective or damaged wiring or high resistance in the circuit also due to damage or corrosion.

**stern2192** · 03-26-2012, 06:06 PM

I am not positive on the brand I am pretty sure they are the stock AC delco, when I had to replace them a month ago it was still under warranty from the dealer I got the car from so they replaced the o2 sensors. But thanks pajeff02, should I go ahead and replace them?

**pajeff02** · 03-27-2012, 03:23 AM

I would clear the codes with a scanner and see if they repeat before throwing parts at it. You can also watch the sensor output on some scanners. After warm up, a properly operating O2 sender's output will rapidly cycle up and down between about 100mV and 800 mv. A sender that does not do this and has sluggish output probably is in need of replacement. Each sender also has a heater element and if this burns out a code will be triggered. Wouldn't hurt to check your wire harness to ensure that it is not damaged and to inspect your connectors for corrosion.