use a hand held scanner and see what cylinder specific code is showing. the onboard scanner will not show cylinder...
The other is an O2 sensor code is it not? please post definitions with all codes and if history or current. And yea clean the TB
The p0300 was pulled with hand held scanner. There are no history codes since I put a new battery in it.
The two possible causes I think I could be facing are ignition coil(s) or I had moister in the fuel lines as it sat in my shop for the last 4 months. When I started it after setting 4mo, it stuttered just a bit then idled fine.
Today I'm going to drive it to town put in some high octane fuel and some Lucas fuel treatment, clear the codes and take it for an hour drive and see what I get. I'll post the results when I return.
The fuel nor additives are going to help. You are probably running 10% ethanol and that will absorb any moisture in the fuel lines.
Try swapping out the coils one at a time with a known good one. If that doesn't help, you may be looking at a new ICM.
Cleared the codes, added fuel injector cleaner and a full tank of premium fuel. Drove it and after 30min of driving, check engine came on. Pulled codes and I'm no longer getting the misfire code but just an O2 code. So I'm thinking that the original misfire p0300 I was getting was due to some moisture in the fuel line from setting 4 months.