Where is the oxygen sensor located on a 2008 Chevy Express?

The location of the oxygen sensor(s) on a 2008 Chevy Express van depends on the engine. There are multiple oxygen sensors, typically one or more upstream (before the catalytic converter) and one or more downstream (after the catalytic converter). They're usually located in the exhaust manifold or the exhaust pipe itself.

To find the exact location, you'll need to:

1. Identify your engine: Check your vehicle's documentation (owner's manual or VIN sticker) to determine the exact engine type (e.g., 4.8L V8, 5.3L V8, 6.0L V8).

2. Consult a repair manual: A repair manual specific to your year and engine will show diagrams and pinpoint the oxygen sensor locations. You can find these online (often for purchase) or at auto parts stores.

3. Use an online parts diagram: Many auto parts websites (like AutoZone, Advance Auto Parts, or Napa Auto Parts) allow you to enter your vehicle's information and view diagrams showing the location of various parts, including oxygen sensors.

Without knowing the specific engine, it's impossible to give a precise location. Do not attempt to locate and replace oxygen sensors without the proper knowledge and tools. Oxygen sensors are delicate and improper handling can damage them or cause injury.