Check engine p0301

A reasonable explanation and possible rectification suggestions on the link below.

https://www.obd-codes.com/p0301

P0300: Random Cylinder Misfire Condition
http://www.autocodes.com/p0300_toyota.html

P0301: Cylinder 1 Misfire Detected
http://www.autocodes.com/p0301_toyota.html

P0304: Cylinder 4 Misfire Detected
http://www.autocodes.com/p0304_volkswagen.html

misfire cylinder number 1 need to check wiring coils plug for the number 1 cylinder
https://www.engine-light-help.com/P0301-check-engine-light.html P0301 OBD II Trouble Code Fixing Misfiring Engine P0301

the P0401 code has to do with your exhaust! Could be caused from sensor to clogged exhaust! The P0301, I believe is misfire, cylinder #1

First you need to retrieve codes from the Engine control module. You can buy a cheap code retriever at harbor freight and get the codes. After you get the codes, if it is P0301 it means cyl #1, P0302 = cyl #2, P0303=cyl 3 and P0304= cyl 4. For ex: if you got P0301 you should remove the ignition coil #1(near the front of the engine, where the pulley is) and change its position with the coil # 2. Also remove the spark plug #1 and change the position with the spark plug #4. Clear the codes and start and run the engine until the check engine light goes on. Check for codes and see if the code change for a different code. If it change the position observe which one is the change. If is P0304 you have a bad spark plug, If it is P0302 you have a bad coil. If it repeat P0301, you have either a low compression, bad injector/connector, bad intake gasket them you should continue your diagnostic. I hope this help you.
Junior.

Code P0301 ts Cylinder 1 Misfire Detected. Check the spark plug and wire on cylinder #1.

The fault code P0301 means "Cylinder 1 Misfire Detected", you can erase the code with related code reader, such as the Godiag T300+ , it has many kinds of functions, but the price is a little expensive.

Hi, I'd focus just on that cylinder for now, unless the other lights come on again. This ought to give you enough information to start diagnosing the problem - http://www.obd-codes.com/p0301 - good luck!

P0301 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #1

P0171 code basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1. - this could be an open vacuum line.

on your P0301 and your P0171, the first thing I would check is your mass airflow sensor, it's probably fouled, also check the air filter, and vacuum lines for cracks.

P1406 code - EGR Valve Pintle Position Circuit - this basically states that the EGR valve is clogged.