ghartman

I have a 96 Grand Voyager that just reached 100,000 miles. I have changed spark plugs in 4 of the 6 cylinders (3.3 liter engine). The two I can get to are the rear center and rear left cylinders. I just bought a new vehicle and am going to sell this one once I get the "service engine soon" light fixed. So I'm not into try this part, try that part.

The P0140 code was read from the computer. The rep at Autozone said this meant to replace the bank 1 sensor 2 oxygen sensor due to no activity detection.

Questions:
1. is this sensor the one between the engine and the catalytic converter?
2. I assume bank 1 is the side of the engine with cylinder 1. but what is meant by sensor 2?
3. I'm thinking I can put a digital voltmeter or scope across the sensor to see if there is a sine wave signal output to the computer. if no sine wave, then replace the sensor, if there is a sine wave the problem lies elsewhere.
4. could the "old spark plugs" be part of the cause of the sensor malfunctioning?

any suggestions, insight or other troubleshooting info is greatly appreciated. I can see the oxygen sensor between the engine and catalytic converter, but so far have not been able to see the connector - I hope I can reach it without tearing apart a bunch of stuff - if required.

Thanks,

Gary

deezel

Sensor 2 means after the cat.
On GM v8's, bank 1 means drivers side - I think the "cylinder 1 side" should be correct.
100K miles is pretty high - best to go ahead and change the O2 sensor.