Have miss in 2.2 Chevy while idling runs fine at road speed?

A misfire in your 2022 Chevy that only occurs while idling, but not at road speed, points to a few potential culprits. It's less likely to be a major engine problem like a bad piston or cylinder head issue since those usually affect performance at all speeds. Here are some of the most common causes:

* Vacuum Leaks: A small vacuum leak can significantly impact idle but may not be noticeable at higher RPMs when the engine is under more load. Check all vacuum hoses for cracks, loose connections, or damage.

* Idle Air Control (IAC) Valve: This valve regulates air flow at idle. A dirty or malfunctioning IAC valve can cause erratic idling or stalling. Cleaning it (if possible) or replacing it is a common fix.

* Throttle Body: A dirty or sticky throttle body can restrict airflow, particularly at idle. Cleaning the throttle body with a dedicated cleaner is often effective.

* Spark Plugs and Wires: While less likely if it runs fine at higher speeds, worn spark plugs or faulty ignition wires could still cause an intermittent misfire at idle. Inspect them for wear or damage.

* Mass Airflow (MAF) Sensor: A dirty or failing MAF sensor can disrupt the air/fuel mixture, leading to misfires, especially at idle. Cleaning it (carefully!) or replacing it might solve the problem.

* Fuel Injectors: A clogged or malfunctioning fuel injector could cause a misfire, but it's less likely to be isolated to idle unless the problem is very minor.

* PCV Valve: A Positive Crankcase Ventilation valve that's clogged or malfunctioning can affect the air/fuel mixture, particularly at idle.

What to do:

1. Check the easy stuff first: Start by visually inspecting vacuum hoses, spark plugs, and ignition wires. Cleaning the throttle body and IAC valve is also relatively straightforward.

2. Get diagnostic codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in your car's computer. These codes can pinpoint the problem area. Auto parts stores often offer free code reading.

3. Consult a mechanic: If you're not comfortable working on your car yourself, or if the problem persists after checking the easy fixes, take it to a qualified mechanic. They have the tools and expertise to diagnose and repair the issue accurately.

Don't ignore the misfire. While it might seem minor now, continued idling problems can potentially lead to more serious engine issues.