O2 sensor heaters...

[skinner]

I have a code for three O2 sensor heater conditions. I replaced 2 of them. Reset codes, and same three still throw codes. IS there an inline fuse or something i'm missing with these things? It's getting expensive and quite annoying tbh.

 

[Wicked_Sludge]

no fuse, but the heat is controlled by the PCM. maybe check all your PCM grounds to make sure they are solid.

 

[skinner]

thanks sludge!
Now, where can I find diagram of all the grounds on this truck? I'd love to get this thing out of the way!
Its weird...if I clear the codes...I can drive it clear to california without the CEL. When I shut it off...then restart it..bam...CEL with 5 codes(3 or 4 of them Oxygen sensor related). Rinse and repeat...
Seems to run well enough...

 

[Wicked_Sludge]

a haynes manual will list all the PCM grounds.

the o2 sensors are only heated until the exhaust system reaches sufficient temps that the o2's will function on their own...so this might explain why the cel only comes on after restarting it cold.