Check engine light on. Autozone said p0157/p0158 low voltage - post cat/downstream. They only show 3 sensors for sale. Bought a Bosch downstream, replaced driver side on the cat. Had autozone reset the codes. Check engine light was back after 5 miles.

Completed a full drive cycle (100+ MILES Highway and city), CEL is still there. Bought Cataclean. Completed drive cycle. CEL is still there.

Got up underneath the truck. Noticed a catalytic converter on my passenger side with an O2 sensor on it.

So do I have 3 or 4 02 sensors? Does autozone only show three sensors because the downstream can be used for the driver and passenger side?

Finding a diagram online has been a pain.

 

That's a wiring problem, not a sensor problem.

 

I have been having electrical issues. All my power outlets fry devices. My clock and radio settings will disappear.

The ground from battery is good. I checked the ground on the exhaust and it's connected. One mechanic wanted $80 an hour to run a diagnostics.

 

Our Dakotas have four O2 sensors (2 upstream, and two downstream), and there are only two different part numbers to choose from. The downstream left sensor has a different part number than the other three, and those other three use the same sensor (part number). Dodge vehicles don't seem to like Bosch sensors at all, so avoid them altogether. I stick to OEM sensors for O2.

How old is your battery?
You might need a battery replacement, when these trucks have a weak battery, all sorts of weird electrical activities will occur.

Welcome aboard.

 

The battery is only a year old. Nobody can tell me why the power outlets are frying everything, especially when the amps/voltage are reading correctly. The alternator is also producing "weird readings" according to everyone who has tested it, but it's not bad.

I have a feeling my electrical issues may be the culprit and it's causing the 02 sensor to produce a code, therefore, I can't pass inspection.

 

If the outlets are frying devices, sounds like a voltage issue.

Kinda related, but had this happen on a motorcycle years ago, The cable to the electrical system had been damaged and electrical system was being run off the alternator only. It fried my headlight twice before I figured it out.