Skip the auto shop - Our mechanics make house calls

Q: Rough idle and RPM fluctuation

asked by on

Helle there I have 2006 audi a4 turbo manuel There is something going funny on the car When i hit the gas pedal RPM goes up and down and loses power That keeps doing everysingle gear (1-6) Can you tell me what it should be?

My car has 156000 miles.

This may be a sign of a faulty MAP sensor. The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a signal that is proportional to the amount of vacuum in the intake manifold. The engine computer then uses this information to adjust ignition timing and fuel enrichment. When the engine is working hard, intake vacuum drops as the throttle opens wide. The engine takes in more air, which requires more fuel to keep the air/fuel ratio in balance. When the computer reads a heavy load signal from the MAP sensor, it adjusts the fuel mixture to slightly more rich than normal so the engine can produce more power. The computer will then retard (back off) ignition timing slightly to prevent detonation (spark knock) that can damage the engine and decrease performance. This may also be caused by other closely related components such as a dirty or failing mass air-flow sensor, a faulty throttle position sensor or potentially a vacuum leak. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your MAP sensor.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Where is the map sensor on a 2001 Montero Sport

Hello - the Manifold Absolute Pressure (MAP) sensor is located on top of the intake manifold, in the middle. This will be between the valve cover and the firewall that separates the engine compartment from the passenger compartment. It's a...

Q: Rough start after putting in gas

Hi there. I would highly recommend reading this article that articulates the source of the P0455 OBD-II trouble code, the possible causes and repair solutions. P0440 is the general code for a problem with the Fuel Evaporative Emission System. The...

Q: I have a problem of petrol going through to the oil sump and the car backfire and some smoke coming out of exhaust.

Hello. If your oil is being mixed with fuel then you are either getting too much fuel into the engine or you have a serious internal engine issue. Most of the time this is caused by worn out piston rings....

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.