How many o2 sensors does the 2003 Chevy Suburban have?

The 2003 Chevy Suburban has four O2 sensors on the exhaust. There are two on the exhaust manifold before the catalytic converters, and two after the catalytic converters. The O2 sensors on Your vehicle are designed to measure the exhaust gasses to make sure that they are in the correct range for operation. When one of them has a problem You will usually notice that Your engine is running rough because it is not able to calculate the correct air to fuELRatio. Usually when an O2 sensor fails You will also get a check engine light at Your dash and You can use an OBD II scan tool to confirm that the sensor has a fault that was detected.