MAP Sensor Problems: What They Are and Where to Find Them

The Manifold Absolute Pressure (MAP) sensor provides a measure of air pressure in the intake manifold so that the engine computer can balance fuel injection and spark timing. If there is a fault, it would make idling be rough, cause stalling of the engine, and be fuel-inefficient, and trigger the check engine light. There has to be a correct reading for performance and economy. Though small, it is a sensor that plays an extremely critical role to maintain your car driving smoothly and nicely. Neglecting the issue of the MAP sensor will also cause long-term engine failure.

Engine Stalling or Surging

If the MAP sensor is feeding wild pressure values to the engine control unit (ECU), then the computer will start making wild guesses about how much fuel the engine needs. As a result, the engine’s computer will produce inefficient air-to-fuel ratios, which will produce surging, where the engine suddenly revs higher without extra throttle, or stalling, especially idling or low-speed. This problem is more severe when in slow moving traffic or stop-and-go driving where engine load is fluctuating constantly. If you’re experiencing these symptoms, take the car to a shop that specializes in auto repair in Hayes, VA to prevent engine damage.

Poor Fuel Efficiency

The MAP sensor helps with fuel economy. When this fails and causes the engine to run “rich” (more fuel than needed), you’ll notice black exhaust smoke, a strong fuel smell, or significantly lower miles per gallon. Or, if it creates a “lean” situation (too little fuel), the engine will stumble during accelerations or when climbing a hill. Either way, you’ll be visiting the gas pump more often, and long-term fuel system damage can occur if not addressed.

Rough Engine Performance

A bad MAP sensor will cause the engine to run erratically, cause the car to vibrate at idle, struggle when you press the accelerator or even stall in use. When the sensor triggers a false reading, air-fuel mixture is out of whack, resulting in incomplete combustion. It puts additional stress on the spark plugs, ignition coils and fuel injectors. If left unchecked the car can become unreliable, produce higher emissions, and lead to more expensive repairs down the line.

Check Engine Light and Trouble Codes

The most common symptom of a faulty MAP sensor is check engine light. The scan will usually indicate with precise fault codes such as P0106 (performance of the MAP sensor), P0107 (low voltage), or P0108 (high voltage). The codes help in determining the fault so that a technician can easily determine the fault. These codes, when not serviced, lead to limp mode, and the engine shuts off power to avoid further harm.

Not listening to a malfunctioning MAP sensor can result in expensive engine repair, bad fuel economy, increase in emissions, and even catalytic converter failure. Well, it is cheap and simple to test and replace a MAP sensor with the proper tools, so if your idling engine is running rough, stalling, or if there is a warning light on the dashboard, don’t wait. MAF technicians conduct intensive diagnostic checks to repair and diagnose sensor issues properly so your car operates more smoothly and preserves the long-term health of your engine.