Q: My car has a rough idle and misfires once its warmed up

asked by on October 31, 2016

Took screen out of mad sensor and problems started from there misses and cuts out once warmed up can be driving at 60mph and it surges and cuts out while driving then sitting at stop lights it's rough and exhaust is horrible and white smoke out of one pipe and the other blows black stuff out also changed plugs and wires checked then a week later and one side was fine the other was black

My car has 241000 miles.
My car has an automatic transmission.

Hi, and thanks for contacting YourMechanic. First of all, the mass air flow (MAF) sensor requires its screen; the air registering through the sensor is monitored with the elements in the screen. By removing the screen, you actually destroyed the sensor. I recommend replacing the MAF sensor before testing anything else on the vehicle. If you need assistance troubleshooting this issue, or the problems continue, then seek out a certified technician, such as one from YourMechanic, to assist you with your rough idle and engine misfires.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

What should I do if I can’t shift out of park?
Like most other modern vehicles, yours is equipped with a safety system designed to prevent you from driving if the Brake Lights aren’t working. However, there are times that this system may malfunction. If your car won’t shift out of...
Car shakes when air turned on
There are a few components that could cause this abnormal shake such as the motor mounts, belt pulleys and spark plugs. The most common cause of the shake being from faulty motor mounts. I suggest having a trained mechanic, such...
Car shuts off when the weather is hot
Hello. A bad cam position sensor will cause a Check Engine Light to come on and possibly cause a stall or no start condition for your 2000 Mercury Mystique. Cam position sensors (https://www.yourmechanic.com/services/camshaft-position-sensor-replacement) usually develop their problems when hot, so this is...
Why is there a squeaking noise after an oil change?
Hi, thanks for writing in. It is possible that you could have accidentally spilled a little bit of oil on your serpentine belt. If this is the case, the noise will eventually go away. If it does not, you can...
Whistle noise from air conditioner
Without hearing the noise myself I would say the noise is due to the blower motor is noisey and need to be replaced. The noise may be from debris in the blower motor and it needs to be cleaned out...
2014 Ford c max hybrid
The “check fuel fill inlet” warning light means that there is a problem with the fuel tank fill seal. The seal could be missing, loose, damaged, distorted, or there is debris in the fuel fill inlet, and/or there is a...
my car starts but boggles out and stalls if i give it to much gas. almost as if the engine is choking
Hi there. In general, engine performance and the traction control issues you have described are not related. The crankshaft position sensor would cause misfiring or an inability to start; but in general, typically does not cause bogging or acceleration problems....
Do you think with what I have described that that is the problem
Hi Future. Thanks for the follow-up question. Based on the symptoms you're describing, I would assume you have multiple issues beyond the crankshaft position sensor. The thing about engine codes is that they are simply recording facts on systems that...
I've been having issue with smoke coming out my exhaust now it's smoking from my converter
Your exhaust can get to over 500 degrees F. It should not be touched by hand or can cause burns. You should check to see if the coolant or engine oil is getting low to see if the engine has...

Related articles

The Check Engine Light Demystified
Your car Check Engine Light can mean many things. The Check Engine Light comes on when there's an electrical or mechanical problem with your car.
Symptoms of a Bad or Failing Speed Timing Sensor
Common signs include the transmission having difficulty shifting, Check Engine Light coming on, vehicle not starting, and loss of engine power.
How to Replace an Evaporator Temperature Sensor (Switch)
The air conditioning system has an evaporator temperature sensor that fails when there is no cold air or the air conditioning is inconsistent.