Skip the auto shop - Our mechanics make house calls

Q: Random misfiring. Check engine light is on. Running real rough. Bad PCM?

asked by on

The check engine light is either on or blinking the engine is running real rough different lights on the dash go on and off and very loud when driving. Wants to stall at idle, shakes badly. Changed out the spark plugs and had absolutely no effect.

My car has 156000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. There are severa...

Hi, thanks for writing in. There are several malfunctions that can cause a rough running condition. The spark plugs could be an issue, but it could also be a problem with the ignition, a fuel supply problem, or even a wiring issue. It would be best to have a certified mechanic, like those available at YourMechanic.com, to perform some diagnostics on the vehicle to identify exactly what is causing the rough running condition.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: My truck wont start. I was driving it earlier and a big cloud of white smoke came out of the exhaust and it completely shut off

Hello and thank you for contacting YourMechanic. White cloud of smoke from the exhaust means that the engine coolant has gotten into the combustion chambers of the engine and is burning the coolant. This could be caused by a blown...

Q: Car misfires, with a P0306 code 2001 Dodge Intrepid 2.7L

Hello - I note that you do not mention replacing the plug wires and plug boots. If these components were saturated with oil by the leaking valve cover gasket, they may still be shorting out, even with new plugs and...

Q: Misfiring - 1998 Buick Century

Hi there. First thing to check is whether there are problem codes, even if the Check Engine Light is not illuminated. Yes, a likely problem with the misfire is the coil packs, which may or may not set a problem...

Related articles

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
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.