O2 sensor question

[spraymonkey]

I have a 96 ford ranger 4x4 xlt with a 4.0, My issue is the CEL with codes
P0153, P1151.

The maf has been cleaned, has a new fuel filter and it seems to run just fine, Im thinking it is the 02 sensor itself because the CEL will turn on for about a day or so then go off for another day or 2 then turn right back on. Not sure if anyone else has had this problem but i could use some insight on what i should be looking for, oh and i have also checked for vacuum leaks and found none.

 

[adsm08]

You are probably right.

Your codes are for slow or no switching of the O2 sensor signals. Oxygen sensors live in a harsh environment and wear out after a while. When they wear out they start by switching slowly and then dying.

Most manufacturers say to replace them after about 100,000 miles of service as a maintenance item.

 

[spraymonkey]

Thanks man that makes alot a sense, and the truck has about 158k on it and i just replace the downstream 02 due to some nutjob who had the truck before just cutting the wires and hanging them up above the heatshield for the exhaust, so i guess im just gnna replace both the upstream and call it good for the time being lol.