Where is the O2 sensor on a 1994 Chevy Suburban 1500 350 V8 engine?

The exact location of the O2 sensor(s) on a 1994 Chevy Suburban 1500 with a 350 V8 can vary slightly depending on the specific engine configuration and emissions standards in your region. However, they are almost always located in the exhaust system downstream of the catalytic converter(s).

Most likely, you'll find at least one O2 sensor in the exhaust pipe after the catalytic converter. There might even be a second one further downstream. To locate it, you'll need to:

1. Consult your vehicle's repair manual: This is the best resource. It will provide diagrams and precise locations.

2. Look under the vehicle: Carefully inspect the exhaust system, particularly the pipes exiting the catalytic converter(s). The sensor will likely be threaded into the exhaust pipe and have a wire harness connected to it. It's usually a cylindrical device, often with a single wire (older systems) or multiple wires (newer systems).

3. Use a diagram: Online resources like repair manuals (some are free online, others are subscription based) or parts websites (like AutoZone, Advance Auto Parts, etc.) often have diagrams showing the sensor's location. Search for your specific year, make, model, and engine.

Important Safety Note: The exhaust system gets extremely hot. Allow the vehicle to cool completely before attempting to locate the O2 sensor. Wear appropriate safety gear like gloves.