Skip the auto shop - Our mechanics make house calls

Q: P0302 code & car makes puttering noises

asked by on

The P0302 code is showing. The spark plugs are good - my mechanic checked them. At low speeds, in town, the car literally goes putt-putt-putt. I want to have the IAC valve changed. Do you think that's a good idea?

A: Hello. The P0302 diagnostic trouble code in...

Hello. The P0302 diagnostic trouble code indicates that a misfire has been detected on cylinder 2. Before changing the IAC valve, it would be a good idea to address the P0302 diagnostic trouble code and have the spark plugs, spark plug wires, ignition coils, or ignition control module inspected. This may solve the problem. If you aren’t getting a diagnostic trouble code for the IAC valve, then it may not need to be replaced. The P0302 trouble code is commonly resolved by having a tune up completed on the vehicle. Keep in mind that there are times when this trouble code is caused by a faulty fuel injector, burned valves, or a dead engine cylinder. I would suggest that you have an inspection of the misfiring condition completed by a certified technician, such as one from YourMechanic.

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: Valve cover and misfiring cylinders on 6 and 7 (needs a tuneup) 2011 Chevy Silverado 1500

Hello - yes, oil leaks onto the plugs, or onto the coil boot over the plug, will cause misfires and poor running. I would recommend a valve cover gasket replacement by a mobile, professional mechanic, such as one from YourMechanic,...

Q: Misfire caused bad o2 sensor?

As you may know the oxygen sensors which are part of your emissions system read exhaust gases to determine whether or not the appropriate amount of oxygen is present in the exhaust. Based upon this reading, this information is relayed...

Q: 2005 GMC with Denali transmission grinding in all gears including neutral. It will not accelerate and also doesn't have park.

Hi there. Your transmission is slipping all of the gears inside and may be due to a broken stator clutch and a broken torque converter. A torque converter that has failed will cause a grinding noise if the stator breaks...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...