Q: Car misfiring, running rough.

asked by on January 06, 2016

My car is running rough. The codes say I have a lean mixture and I am having misfires in the cylinders.

Engine is misfiring Inspection $94.99 - $114.99 Get a Quote

The lean codes on this engine could mean you have a lean condition that the computer sees as a problem. The computer would need to be scanned to see if the mass air flow sensor is reading correctly. The sensor normally gives a reading to the computer of the cars altitude or barometric pressure. If the reading output does not match the local pressure the sensor may need to be replaced. I have seen sensor readings equal to 10000 ft above sea level when I was at 10 ft above sea level. This will cause the computer to send less fuel to the computer and would cause lean codes. In this case, a mass air flow sensor replacement fixed it.

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

Wire harness problem
Hello. Depending on which wiring harness it is, the source of the power needs to be checked. A continuity check of the wires also needs to be done to make sure there is no break in the harness. Electrical problems...
Key not starting car
Hi, it sounds like your battery is too low on charge to get the engine started. The battery would still be able to power lights and other small things, but turning the engine over takes a lot of power. If...
Clutch issues
I have seen some flywheels that after the resurface is done and the clutch and pressure plate is installed the bolts will bottom out and not fully seat the pressure plate. This will cause the clutch to not disengage all...
Door ajar light on and doors only manually lock
All of the lock functions and rear wiper functions are controlled by the Body ECU. If the ECU is failing this could be the source of the issues. In the front door and in the rear door, there are both...
power steering not working
You probably know this already, but I must mention that driving with the faulty power steering is very dangerous. This is definitely not an issue that can wait. The trouble could be in the power steering pump (https://www.yourmechanic.com/services/power-steering-pump-replacement), belt/tensioner (https://www.yourmechanic.com/services/drive-belt-tensioner-replacement),...
"Fluttering" noise under heavy throttle/boost
Hello, thanks for writing in. If this occurs only under this high load condition then most of the time it is caused by a boost leak. I usually suspect that the intercooler has a crack as that will cause this...
How do I repair srs code b0108?
Hi there. When you get this code it is typically due to a failure of the passenger side air bag. Th air bag fails internally causing this light to come on. It can also be a circuit failure so I...
Can I swap a 97 4.3 with a 94 4.3?
Hi there. You can change the engine block, but the cylinder heads will not match up. The cylinder heads for a 94 was made for an intake with a throttle body and injection in the throttle body where the 97...
My catalytic converter was replaced and everything seems fine. However the engine seems incredibly loud and this occurred on the highway.
Hi there. There is an exhaust leak under the vehicle. Check the catalytic converter, muffler, and all the clamps under the vehicle on the exhaust pipe and see if anything came loose. Hook up any parts that are disconnected on...

Related articles

2012 Ford Mustang vs. 2012 Dodge Charger: Which One Should I Buy?
Technically these two vehicles have wildly different classifications: compact for the Ford Mustang and large car for the Dodge Charger. However, who would consider either one anything other than a muscle car? These cars are meant for speed, fun, and...
The Top 5 Selling Cars in Delaware in 2012
Delaware Delaware offers a variety of weather, which means drivers have to be prepared for both the mild and the treacherous. In previous years, the best-selling vehicles have included the Honda Civic, Accord and CR-V, along with the Toyota Camry....
How to Drain Your Fuel Tank
The The majority of cars on the road today use internal combustion engines that use gasoline or diesel as fuel, and they store this fuel in a gas tank. Most gas tanks are located on the undersides of the vehicle...