Other P030 errors point to other cylinders not working correctly.
For example, P0302 code is spark plug 2 misfire, and P0303 would be spark plug 3.
P0301 Error Code Causes
- Bad Spark Plug
- Spark Plug Wires
- Bad Coil
- Fuel Injector
P0301 Error Code Fixes
- Check the spark plug wires, coil pack, and injector.
- Check the spark plug wire.
- Check the spark plug.
- Test the Fuel Injector.
- Swap Parts with Working Cylinder.
Often the problem wont be visible but is a good place to start plus it helps to know their location.
Many mechanics will swap the spark plug with another one to see if the problem follows.
If the plug wires are swapped be sure not to mix up the firing order, take pictures if necessary.
Sometimes the spark plug will be old and need to be replaced.
Often, something else is causing the plug not to get power for a spark and will have a lot of build-up.
A bad Fuel Injector can also be the problem.
Again an easy way to check is to swap it out with a known good one and see if the problem follows
A low-cost way to narrow down the problem is to swap out parts one at a time with a working cylinder.
For example, if cylinder 2 is working swap the coil pack and see if the problem follows.
If the P0301 clears but a code P0302 comes up after the swap you will know the coil pack is bad.