POO31 Intermintent ??

I got a POO31 and cleared it a week or so later it came back and cleared itself and hasn't come back. Wondering how it could come and go ? Should I replace the O2 sensor ? Is DENSO 2349050 the correct part ? Any response appreciated.

 

What year is your truck, and how many miles does it have on it?

 

2008 2.7 135K

 

Hope this helps you George: https://www.obd-codes.com/p0031

The o2 sensor is one of those parts you want to only replace with OEM and not use an after-market part. ~ Good luck, Mark

 

I'm not familiar with your year, but that O2 sensor should have four wires. Two for the O2 sensor and two for the heater (in the O2 sensor). Check that all of your wires are making good connections and that you have a 12 volt supply to the heater.

 

98.993423% chance that replacing the sensor will do the trick (and concur with the OEM only recommendation above), BUT... definitely look up the specs for this check the heater circuit supply power and ground, resistance across the heater element, and 5v signal & ground. The whole testing procedure should take <5 minutes (4 of which will be spent getting the connector apart). If you are missing power or ground, then you need to start looking for that problem, but at 135K, the sensor itself is definitely the probable culprit.

 

Thanks for the LinK !

 

Thanks for steps to follow - appreciate it.

 

Thanks for listing the moves to make.

 

Just wanted to thanks all you guys that answered the post - I really appreciate it.

 

How would I know which pins to check for the points you mention ?

 

Wiring diagram. If yOu don’t have OEM, someone here can probably post it, or buy Haynes or Chiltons

 

OK, Thanks I'll check.

 

Just curious George if you have an update in case I ever have the same code, did you end up replacing the O2 sensor, or was it wire-related?

 

I put Techron in it - cleared the code - got thru inspection - so I'm good for two years til the next inspection - so pressure is off - I'll let you know when there is anything else to report.

 

OK, Thanks for the update, hope the code doesn't return.

 

X2 on that.