Quote Originally Posted by Fast355 View Post
4 wire is better because it uses an isolated ground back to the ECM rather than relying on the sensor body and exhaust to ground it back to the ECM. The 02 sensor ground usually goes back to the block through the harness on a TBI.
Out of curiosity, what would be a part number or vehicle to look up for a 4 wire O2 sensor that works with the TBI system?