Thread: Oxygen sensor

Originally Posted by gruntfuttock

I have a question,

I had a bit of water get into the air filter box a while ago. (The fender wanted to go though a large puddle while all my efforts to get it to go around were to no avail.) The oxygen sensor just after the air cleaner got dirty as well. The motor coughed a bit, but only a high RPMs.

The vehicle still runs, and I know I was very lucky, but my question is this. How do I know if the oxygen sensor is still working and is still intact and not damaged?

If I disconnect the sensor or have it connected there is no change in the motor or how it behaves.

I cleaned the sensor very carefully, with a squirrel hair brush, (that is the softest brush you can get) carby cleaner and alcohol ISO. so it is clean now, and nothing was damaged in the cleaning. However I feel the turbo a lot now where as before I did not.

I took it to a LR mechanic, he said it was OK but I am not convinced.

What is your opinion?

BTW SWMBO did not want me to spend money on buying a snorkel, now however she is all for it, after i told her just how came close we came to spending $15,000 for a new motor.

I know on a petrol engine the oxygen sensor is in the exhaust i dont think diesels are that much different

If you are referring to the Mass Airflow Sensor (MAF), you can chweck it by identifying the output wire from a wiring diagram, and attaching a volt meter to it.
Rev the engine and the voltage should rise. If it stays the same the sensor is dead.
On a V8 there are two wires with a voltage or rather 3 ( one is the 5volt input). one is a reference that does not change ( idle mixture about constant 0.6-1.5V)) and the other is the signal.
I would not think a diesel would need reference.

Regards Philip A