There is the GM Technical Service Bulletin about aftermarket alarm systems. I only have TSB's available to me in a. Pfd (adobe reader) format and have not been able to successfully post them on here. Send me a private message with your e-mail address and I will send you all the information I have.
As for the mass air flow sensor, with only a P0300 code it is not a "usual suspect." A faulty mass air flow sensor will normally give a code for the mass air flow sensor, a code for running rich/lean or a code for poor converter efficancy. You can check the screen at the opening to the mass air flow sensor (remove the fresh air intake from the mass air flow sensor and there will be what looks like a window screen covering the intake part of the sensor), if it is dirty you could carefully remove any dibris with a shop vac and clean the screen by spraying it with a "fuel injection safe" choke and carb cleaner. Also be sure to check and change your air filter regularly.
Do you have the ability to check your fuel pressure?
This is a very important to any drivability diagnosis. As I posted earlier it should be between 52 to 59 psi with the key on, engine off.
For information purposes, what part of the country do you live in. Most people do not factor this into the equasion, but different regions have different fuel mixture. If you live in the midwest where E85 fuel is prevelant and your vehicle is not flex fuel rated you should not use E85 fuel, the high alcohol concentration can give you drivability problems like you describe, also long crank time and no start situations. Fuels in the N.E. (Where I am) have a large concentration of sulfer that can cause drivabilty problems and problems with the fuel level sensor.
Just a few more ideas. Send me that message with your e-mail and I will get you some more info.
Tuesday, October 23rd, 2018 AT 6:32 PM