P0151 code in 2002 Chevy Astro Van AWD

My check engine light is on steady. When the tech ran the code he originally got the 0151 and correlate to the Crankshaft position sensor, he then switched the key on and just got the 0151.

Does anyone know which O2 sensor this is, and if it is a manifold sensor which side it would be on?

Thanks

P0151 means 02 Sensor Circuit Low Voltage (Bank 2 Sensor I)

That is the first sensor downstream from the exhaust manifold on Bank 2. Bank 2 is the side where cylinder #1 is not on. More info on Bank 1 vs Bank 2:
http://www.obd-codes.com/faq/what-is-ba ... bank-2.php

Do you know which side of the engine cylinder #1 is on? You didn't say what engine you have. Check the wiring leading up to the sensor and if looks good, then I would recommend you replace the oxygen sensor.

It's also a good idea to replace all the oxygen sensors at the same time. It's not required though.

The P0151 code is almost identical to P0131 - the P0131 is the same description but for bank 1.

FYI, this P0131 article may help you as well:
http://www.obd-codes.com/trouble_codes/ ... nsor-1.php

Keep us posted!

It has a chevy 4.3 Vortec engine.

Thanks for the info, I should be able to figure it out.

Out of the two manifold sensors, how do I know which one is low voltage? would an auto parts know this, or would they just have two part numbers for the two different manifold sensors?

I'm not sure what you mean by two manifold sensors? Do you mean oxygen sensor? I'm not familiar with that engine.

There are three sensors on the exhaust. The one upper one and the after-cat sensor are the same part # the other manifold sensor is different. I now know which one is throwing the code, but I don't know which part # it is.

Offhand I don't know what the "manifold" sensor is, I'm guessing it has something to do with the EGR system. The "same" part numbers are for the oxygen sensors (one in front and one behind the cat).

As I said earlier, inspect the wiring to the oxygen sensor in front of the catalytic converter on the Bank 2 side. If the wiring looks good, replace the sensor. You can get that part number from any dealer or parts store (wherever you buy the sensor)

I went to gm-parts direct and found that they differentiate between Right and Left sides and upper and lower.

The Right side of the vehicle is the passenger side correct?

Thanks

Bank 2 is the passenger (right) side.

Well I replaced the oxygen sensor, but now get P1345 which I think is the Crankshaft position sensor. I took it out and cleaned it, but it is still running rough and misfiring (sometimes). Since it doesn't always do it I think I could rule out a timing chain problem.

Let me know if you have any ideas.