Jochy

I’ve been dealing with this issue a few months since I got this check engine light scanned with my durametric scanner.

P0139
P0141
P2318



I did replaced all four (4) O2 sensors (specific Bosch thru PelicanParts) and checked both banks fuses, all good.
i’ve just found on my research that a “check your wiring harness” is the answer after replacing sensors and CEL popping up.
i did replaced the specific bank 1-sensor 2 twice, blaming the first sensor to be the culprit but then I realized that’s was a deliberated wrong decision because didn’t check it’s resistance before deciding to swap it.
Anyway, I really doubt this is a sensor problem.

Therefore, my question is, what’s the best or recommended steps to check vehicle wiring harness at all?
This is what i already djd:

I checked resistance for the heater element side of the sensor and i got expected resistance values expected to see for this bosch sensor.

(I know durametric can read this for me, but I’m not too proficient with this software)

And on the vehicle wiring harness side, I did got right voltage values read with my voltmeter.

Am I missed any other troubleshooting step?
I’m afraid to loose my cat if this problem persists.

Any recommendations is greatly appreciated

Josh

Jochy

If someone has gone thru this issue, I would appreciate your advice

Josh

Jochy

Can anybody chime in to my observation?

Jochy

Bump

Petza914

Looks to me like you may have an ignition coil issue which could be manifesting in a plug that's not firing and that may be what's causing the O2 sensors to throw codes from unburned fuel that's making it into the exhaust. Do you do used oil analysis on your oil changes? If so, how long have these codes been present and what fuel dilution percentage do you see in your UOA reports?

With the Durametric hooked up, turn on misfire tracking for the 8 cylinders and see if one of them is logging some misfires. If so and that's on Bank 1 of the motor - same as the one logging the O2 sensor errors, that's a pretty good bet you've found the problem.


P2318 Ignition Coil G Pri Ctrl Circ Low

Attached is a PDF with all the OBD2 P codes and descriptions.

Coleman

Did you ever figure out what was causing the problems?