Sensor 2 is the downstream sensor ... OBD I engine management, dating back to 1980, used just one upstream O2 sensor, mounted in the exhaust manifold, as close as possible to the cylinder head's ...

We may receive a commission on purchases made from links. Modern cars are designed to be more efficient and eco-friendly than ever. Automakers build vehicles with a wealth of advanced features to ...

ANSWER: Lazy upstream (in front of the catalytic converter) oxygen sensors will affect gas mileage. The downstream (in back of the catalytic) monitors the catalytic converter on most vehicles and ...

The fuel management system monitors the converter by using the readings from both the upstream (pre-converter) and downstream (post converter) oxygen sensors. The sole purpose of the downstream ...

Most modern vehicles have at least two O2 sensors: an upstream sensor and a downstream sensor. These devices monitor the oxygen content in the emissions that leave the engine, as well as those ...