P0300 Pontiac -

Question

Cylinders 1 and 3 are "dead" when I unplug the fuel injectors the engine keeps running. I don't know what the problem is. I've replaced the ICM the MAF all 4 spark plugs and boots and just replaced the battery. I just can't fix the problem. If anyone knows what might be the issue please help me out.

Answer 1

P0300 Random misfire.

You replace the ICM, these have ignition coil inside.  The best way is do a compression test, if the compression is less than 90 psi this would be a mechancial problem .

 Do a compression test the minimum is 90 PSI.