What Causes Rich Fuel Trim?
2 Answers
The reason is that the air-fuel mixture is too rich, and there may be an issue with the oxygen sensor. It is necessary to have it inspected at a 4S shop, as these problems can be repaired. The LaCrosse adopts Buick's latest family design language, featuring smooth and elegant body lines and a highly dynamic body proportion. The full LED automatic sensing headlights with wing-shaped design use Evonik material to create a uniform light curtain effect. More details are as follows: Fault: A phenomenon where the equipment "loses its specified function" or poses a safety hazard during operation due to certain reasons. Failure is sometimes referred to as a fault, or the loss during equipment operation can also be considered a fault, but these faults are repairable. Specified function refers to the function clearly defined in the equipment's technical documentation. Explanation: A phenomenon where the equipment "loses its specified function" or poses a safety hazard during operation due to certain reasons. Specified function refers to the function clearly defined in the equipment's technical documentation. Failure is sometimes referred to as a fault, or the loss during equipment operation can also be considered a fault, but these faults are repairable.
I've been driving for over a decade and have encountered rich fuel trim issues multiple times. The main cause is usually faulty sensors, particularly the oxygen sensor and mass air flow sensor, which are responsible for measuring exhaust and intake air. Once they malfunction, the engine control module mistakenly thinks there's insufficient fuel combustion and commands the fuel injectors to spray more fuel, resulting in an overly rich air-fuel mixture. Additionally, aging or cracked vacuum hoses causing air leaks can lead to rich conditions since the air volume decreases while fuel supply remains unchanged. Faulty fuel injectors that are stuck or leaking can also exacerbate this problem. This condition causes sluggish acceleration, doubled fuel consumption, and thick black exhaust smoke. Prolonged exposure can even damage the catalytic converter. I once wasted hundreds on unnecessary fuel costs before fixing it by replacing a sensor at the repair shop. So I advise fellow drivers to regularly maintain their sensors and address minor issues before they escalate.
