Have an LS1 in a 65 impala. finishing the project and starting to get the gremlins out.

Engine has Street and Performance headers. PCM was programmed to get rid of o2 sensors.

Car was running fine with no exhaust. It was loud, but ran fine. No codes for 100 miles.

I had an exhaust put on it. When I picked it up, the check engine light was on. Engine threw two codes. One was n/a and the other was p0300. I have reset the PCM twice and the same code has come back when I accelerate hard.

I have checked the fuel pressure (60 psi at rail), and fuel injectors (all cleaned and flowing nice). Since these seemed acceptable, I moved onto the ignition.

After asking several friends, they recommended checking the spark plug wires. I set my ohmmeter to 2k scale then proceeded to record the results. 5 of the plugs came up at .030. Three of the wires read other readings, one .300, one .150, and the third .250.

Am I correct that these readings are telling me the plug wires are bad?

These were custom wires made by Scott Performance Wire.