my Chiltons manual says, " the powertrain control module (PCM) must be reset after reconnecting the battery. Start the engine and hold it at 3000 RPM untill the cooling fan comes on, then allow the engine to idle for about 5 minutes with all accesories OFF and with the transmission in park or neutral."

i have disconnected my battery many times and never did this. as far as i know my engine is running normally. what does resetting the PCM do?

 

Isn't that another word for an ECU? If that's the case, your ECU measures incoming fuel and air, sees if there's an increase in one, the other, or both, and compensates it's fuel maps accordingly.

 

so if i actually reseted my pcm correctly, do you think it would really make a difference?

 

No I don't. If I'm correct, you're not really going to see a difference unless you start dumping a whole lot more fuel, say for a turbo application.