P0301 Cylinder 1 is misfiring

Check this first

If the check engine light is flashing, stop driving – a misfire quickly ruins the catalytic converter.

What usually fixes it

In the order a good shop checks them. Typical total: $81–$3,975 at $130 an hour.

1. Spark plug

   $91–$170

   The cheapest thing that misfires, and the most likely.

2. Ignition coil

   $113–$294

   Swap the coil with the one next door – if the misfire moves, that's your answer.

3. Fuel injector

   $268–$725

   A blocked or leaking injector on that cylinder.

4. Compression problem

   $924–$3,975

   A burnt valve or worn rings – a compression test tells you.

Code titles are the generic SAE definitions. Prices are typical US parts and labor for a common car or light truck – a guide for judging a quote, not a quote. Always confirm a repair against the vehicle in front of you.