30thanni

Been searching around and these are giving the feeling of a big pain in the a**. I believe the p0300 is a vacuum leak... where is the best place to start looking.. I see posts on how to check, and I got my can of carb cleaner ready, but I just want to know where the most common problem areas are. And the p0410 is I'm sure is an air pump replacement waiting to happen. Is this a hard job to do or is it pretty straight forward? Every time I search Air Pump, it gives me the switch and shows me only fuel and water pump replacements. So any advice, comments would help thank you. Car is a 1997 Z28 Automatic.

moparman

The P0300 is a random cylinder misfire code. Many people here have had that code, but no one ever posts back what the problem. Could be as simple as a bad plug wire or plug. Rough roads can also cause a false code to be set.

The P0410 could very well be the AIR pump. IIRC, there was a recall on them.

Injuneer

P0410 indicates that when the PCM cycles the AIR pump, it does not see any evidence of air flow in the exhaust, based on the O2 sensor readings. Could be a frozen check valve, or a melted hose in the system.

As noted, P0300 is random misfire. Have the PCM scanned with a scanner with "GM enhanced parameters". That scanner can pull the misfire count by individual cylinder, which will often point you in the direction of the problem. IF it turns out to be truly random, you have to look at things that can cause misfires on all cylinders - a faulty coil, ICM or distributor, faulty fuel pressure, etc.