I swear I read in a manual to check it by ohming it out. Now that I did, I went to the manuals to check the spec on it and can only find VAC with the engine running. That doesn't do a whole lot for an engine that won't start. lol. Anybody know if I'm remembering right if you can ohm it to check it and if so, can anybody find the spec?

 

I got 355 ohms when I checked it. I would think that would be entirely too high for any sensor, but then again, I could be wrong.

 

Did you test the sensor itself or the wires to the PCM too? And in this case for the 4.9L its a misfire sensor.

 

What codes did you get?

 

You can check it by just turning the engine over with the meter hooked into the wires and set on ac you should get a reading of .3 to 1volt ac while cranking the motor over.

A 355 ohm reading is not to much some GM's read twice that much.

 

just the sensor itself. I don't have a breakout box to test the wires...unless there's another way.

 

P1130 - B1S1 O2 sensor. Just got done replacing it...One busted elbow, half a can of PB blaster and propane later. lol
P0300 - Random multiple misfire
P0385 - Crankshaft Position Sensor B Circuit
P0174 - Bank 2 too lean

I did have P0171 before the O2 sensor went out.

 

I might get around to testing it with the engine cranking, but I have a new one coming in on thursday, so we'll see. I'm still learning a lot on the electrical side, so apparently, I have no idea what normal looks like. haha. Would 355 be considered normal for these then?

 

I have the same specs and procedures as you have, so i would do the voltage test. As long as it reads more than 1.0 volts its good and the problem is in the harness or at the PCM

 

There's almost no way this can be right, but after changing the O2 sensor last night, the truck is running much better. No more no start (today at least) and no barely running then dying. It makes no since at all since it would be in open loop at start up, but who knows. The only other thing I did was take the misfire sensor off to test it. Maybe the harness was a little loose and all it took was me popping it off and put it back on. But, does the misfire sensor control anything or is it just a monitor?