All posts tagged: oxygen sensor

M54 Oxygen Sensor Replacement DIY

Some of the best upgrades you can make to maximize the fuel economy of your BMW include: replacing the spark plugs, keeping correct tire pressures, and replacing old oxygen sensors. The oxygen sensors before the catalytic converters – located in the exhaust manifolds – play a large part in controlling the fuel mixture for the engine. When they have high mileage or have failed they no longer send a clear signal to the engine’s computer, at which point the computer defaults to a base line map designed to protect the engine. This default map is a rich fuel mixture (extra fuel) which causes sluggish performance and decreased fuel economy.