I installed this O2 sensor on an aged 1994 Ford F250 with a 139000 mi on its 5.0 engine. I had previously replaced the Throttle positioning sensor and the manifold temp sensor, that improved its waning performance. I replaced the O2 sensor when I noticed the increase in gas consumption! The new sensor not only restored the gas mileage back to its normal abysmal state, but it also mildly improved the acceleration.