Where are oxygen sensors on a 1992 Chevy 1-ton pickup truck 2-wd 350 engine?

A 1992 Chevy 1-ton pickup with a 350 engine will typically have one oxygen sensor located in the exhaust system, before the catalytic converter. It's usually positioned in the exhaust manifold or very close to it, on the passenger side (right side in the US).

However, there's no guarantee without seeing the specific vehicle. Some modifications might have added or relocated the sensor. To be certain, you should:

* Consult your owner's manual: It should have a diagram showing sensor locations.

* Look under the truck: Carefully examine the exhaust manifold and piping near it. The sensor will be a threaded device with a wire harness connected.

* Check a repair manual specific to your year and model: A Haynes or Chilton manual will provide detailed diagrams and instructions.

Keep in mind that working under a vehicle can be dangerous. Support the vehicle properly with jack stands before you get under it.