O2 trouble-shooting

[fancyTBI]

1992 C1500 5.7

SES light comes on when truck is warm, throws code 13 for O2 sensor. Shuts off going down road but comes on intermittently and shuts off again. Just started having issues after driving for ~3,000 miles.

Any ways to check the O2? Does anyone have a diagram for the ground? I don't want to buy a new one and have that not be the issue.


Other than that, the truck runs great. I have been enjoying the V8 swap.

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[Schurkey]

1. Connect a REAL scan tool and observe the data readout.
2. O2 voltage will be listed. Needs to vary fairly rapidly from almost 1 volt to about 0.2 volts, or anywhere in between as long as it's above and below 0.5 volts.
3. Rich/lean will probably be listed. The truck should be flipping back and forth between rich-lean fairly rapidly.
4. O2 crosscounts should be listed. They may use another term, my scan tool calls it "crosscounts". Higher numbers are better--under 10 is getting lazy

For the record, I fought a highway-speed "lean" condition for two friggin' years before I was smart enough to ****-can a $13 O2 sensor that was providing FALSE LEAN readouts. I tested everything and got nowhere, because the O2 sensor provided accurate info at lower speed/lower load, and everything else I tested was good.

 

[fancyTBI]

I'll have to get my hands on a scan tool. Thanks for the info. I think this one is a cheap off-brand from Advance Auto. Never had any problems before with wiring or grounds. I just kind of assumed that it was a bad sensor. But I do need to get a scan tool.

 

[fancyTBI]

First I checked all the connections and loosened the O2 to see if it would ground better in the bung. I had the battery unhooked while doing so. Long enough for it to reset the computer. Now I have a surge at idle that was not present there before. Could the failing O2 cause this? SES light comes on, still for O2. New one will be in tomorrow. Any help here? Not sure why it would start after unhooking the battery. Drove for 40 miles, IAC should have learned idle by now.

 

[fancyTBI]

SOLVED

Cheap O2 sensor failed. Replaced with a AC Delco brand and it works flawlessly. No code 13 anymore!

The idle was also solved after I cleaned the IAC and gave it time to reset it.

By the way, the O2 sensor I got from a local dealership (Vaessen Bros. Chevrolet) and it was only $60 out the door. Parts stores were going to take 2 weeks or more to get it, charge me shipping, and then it was over $100 for it. I've had too many parts fail from Advance and O'reilly, so I wanted to get a Delco brand one this time.

As always thanks for the help from @Schurkey. Hope future members or owners will find this thread useful.