Hello all, I have a 4th gen ES330 that’s been flashing a P0301 error for a couple of days. No problem with the car besides the occasional shudder when it’s on low temp just starting up, but no issues when it’s running to spec.
The other day I replaced cylinders 1, 3, and 5 spark plugs and ignition coils to clear the error code, and also because this car hasn’t had work done on the spark plugs in years because I bought it off an older woman and I figured if I already had access to the cylinders then I may as well replace all of them.
Once I put everything back together I drove it to work (about 1.5 miles) and on the drive home it felt like my engine was going to shake itself off the motor mounts and the check engine light was flashing. Checked codes and again its the same cylinder 1 misfire. Does anyone know how to test the power to the coil?

 

Swap the coil with another cylinder and see if the error tracks w/the coil.