Skip the auto shop - Our mechanics make house calls

Q: Idle issues or MAF sensor? 2001 Nissan Maxima

asked by on

My 2001 nissan maxima has 270 000 plus miles and ive been having issues with performance...the engine seems to not want to turnover when car is cold and i notice it runs very rich..i can smell gasoline during idle..also while idling it sometimes idles very rough with occasional spikes..sometimes it will idle up and down contiunously until i put it into gear..struggles on inclines and i notice it doesnt have the power it should...took it too advance auto and had them put it on code reader...threw codes for idle air control system..oxygen sensors b1s2 b1s1 and air fuel mix ration sensor...please help dont know where to start!!!!

My car has 270000 miles.
My car has an automatic transmission.

A: The idle air control valve monitors the air...

The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine. This valve is controlled by the vehicle's computer which will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed. However, when the engine RPM drops below the normal range of 800 RPM (for most cars), it is a sign of a failing idle air control valve. In cases where this valve is clogged or is failing, your vehicle will stall instead of slowing to an idle after the release of the throttle or in some cases idle erratically. I would recommend having an expert from YourMechanic come to your home to replace your idle air control valve.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Car runs with the mass airflow sensor unplugged. If you plug it in it will die if the car is running.

This is a sure sign of a shorted mass airflow sensor. The reason it starts with it off is the computer sees no mass air signal and replaces it with an internal memory fake signal to use. This will let...

Q: Toyota Venza 2000 idles at high RPMs

Watch my video "how to fix a car that idles poorly." A lot of times, it is that simple. You take the air duct work off that goes into the throttle, get the rubber duct off, get some spray throttle...

Q: My car starts to run hot if I cannot maintain a consistent speed where air is moving across the engine.

Hey there, your car has an electric cooling fan. It should start automatically when the engine gets to a certain temperature or when you switch the A/C is on. In hot weather with the A/C on, the fan should switch...

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.