Q: When I stop at the stop light or a stop sign my car shuts off.

asked by on

I had my computer reprogrammed in November because my car wouldn't start. Then in December my car should like it was idled too high so I got new spark plugs, air filter, spark plug wires, pcv valve, fuel filter on my car because my car was shutting off whenever I stop. I googled and found your website so I booked a service which I thought they would diagnose my car and fix it on the spot all he did was diagnose the car and told me I had various codes and I needed 2 oxygen sensors and that was the reason my car was cutting off. I booked the service and the guy fixed the oxygen sensors and the car was fine when he drove it. I took my car for a ride and it cut off again!! I don't know what else to do? What else could it be?

My car has 195 miles.
My car has an automatic transmission.

It sounds like you may have a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer and will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. This is also an important function when starting the motor as it allows the motor to run and idle on it’s own once the motor fires. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed while adjusting the air/fuel ratio constantly to allow this to happen smoothly. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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
  1. Home
  2. Questions
  3. When I stop at the stop light or a stop sign my car shuts off.

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: how much would it cost for a fuel replacement ?

If you put diesel fuel in your vehicle I would strongly recommend to have it replaced. If you accidentally put premium gas in your vehicle when it only requires regular, you should be just fine with that and won't have...

Q: Clutch pedal sticking

I have seen this problem before. Since the issue seems to be temperature sensitive, or prevalent during times of heavy use like traffic, it might be the fluid in your clutch master cylinder is getting too hot. The fluid in...

Q: My truck was getting codes of P0300 & P0420 & P0430. My truck can't go over 40/45MPH without jerking 1997 Chevrolet Tahoe

Hello - the first task is to check problem codes to see if the P0300 (misfire) code is still present, or others. If so - which seems to be what your description indicates - you may have ignition coil, crankshaft/camshaft...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...