I bought the S10 to be something to tinker with. I wanted something to occupy my mind that wasn't just work and house
and so far it's been fitting the bill. What have I been up to?
Other than the interior parts I mentioned, there's a few issues I've been wanting to diagnose. One is a random CEL that comes and goes, the other is an intermittent ABS light.
The dude I bought it from told me about these, and claimed it needs a new rear O2 sensor (which he had and gave me) for the CEL, and the ABS light he claimed was a wheel speed sensor. Trust but verify is my motto, so I wanted to see how I could verify. The truck is a 2000 model year, so it has OBDII with a reasonably modern ECU. How much could Torque Pro tell me?
Well, at first, not much. It read the CEL and spit out a 0420 code, which a quick google search indicates is a catalytic converter failure. There were no codes returned for the ABS light. Awesome. Apparently, these GM ABS systems are notoriously difficult to read codes from, only certain software/readers can do it. I'll find a way.
Torque pro has a data logging feature, and you can select just about every parameter to log. I went through the list and found O2 sensors and wheel speed sensors. That should tell me what I need!
For the CEL, I did some reading on the error and essentially, the upstream and downstream O2 sensors are reading the same indicating the cat is doing nothing. I read that sometimes it's an O2 sensor that's giving false readings, or other times the cat is legit bad. The cat has a visible date code of 6/2019, so it's not original. That doesn't mean it's not bad, but I'd be surprised if it were because the truck is running great. It's very possible that it was gutted, but the truck passed CO smog this time last year, and the PO didn't seem like the type that would gut a cat.
For the ABS light, it's either the ABS module (that I can send out to have repaired for $130) or a wheel speed sensor.
So knowing what I needed to measure, I fired up torque, plugged in my fancy $10 OBDII reader, started logging and went for a drive.
O2 sensors rapidly fluctuate between 0 and 1, so the data is a bit tough to analyze, but outliers should be easy to see...
That jumbled mess indicates to me that indeed, the O2 sensors are all reading about the same. In the correct state, one of those (the downstream sensor Bank 1 Sensor 3) should be reading lower than the others at or near zero. That's clearly not happening, so I either have a bad cat or a bad O2 sensor. Since I have a new O2 sensor from the OP, I'll try installing it and running these logs again to see if there's a difference. If there isn't, I may need to bite the bullet for a new cat (I don't need a cat here, but I also don't hate polar bears).
Now, wheel sensors. The ABS light will come on if one or more sensors aren't working or reading way off from the others. Since torque can read and log the wheel speed sensors, it should be easy to see if one or more are failing.
Overall, the sensors are reading mostly the same. There's a few points where one is reading way off, but it generally comes back in line. For the ABS light to come on as a result of this, one or many need to be off for a long period of time (I can't find how long, but still searching), but to me these results are about what I'd expect. The event at 256 was where I gave it the beans turning onto a fast moving road, so it's reasonable to expect the sensors would read and catch up at different times. What's really interesting about this event is it was a right hand turn, and it's the right rear wheel that's turning the least...exactly what would happen during such a turn.
It's weird that most readers can't read ABS codes because they can read wheel speed sensors. Must have something to do with where the data is stored and where lights come from. Anywho, I got a great log from the wheel speed sensor and I think I can conclude that the computer needs to be repaired. It could be worth cleaning the wheel sensors, but I don't think any one of them are bad.
deal. Will post up when it comes and I install it.
with Corvettes and making sure part numbers are accurate. I doubt this dude gets many units with Corvette part numbers, so he may charge a premium just for that. 
C7 GS 
plate