2001 grand am 2.4l p0300 and p0172, replaced coils, housing,boots and plugs, and injectors..what else could be?

Pretty good info on video little long but has some good info on trouble shooting p0300. He fixed his problem with new plug and coil connector boot(I think you have changed all that).. He also checked the injector to make sure it was not causing a misfire. Not sure if it helps but the video has some good info.

https://www.youtube.com/watch?v=jW-OLfox5P8

po300 is a random misfire, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why. If it was a po302 this means its #2 cylinder thats misfiring,ETC, But po300 could be any one of the cylinders. check plugs, wires, fuel injectors, Etc. Good-Day!

p1227 Oldsmobile Injector 2 Control Circuit Shorted
p1245 Oldsmobile Intake Plenum Switchover Valve
p1275 Oldsmobile Accelerator Pedal Positioning (APP) Sensor 1 Circuit p0300 Oldsmobile Multiple Engine Misfire Detected p0172 Oldsmobile Fuel Trim System Rich (Bank 1)
sounds like bad injectors for one and computer needs relearned or replaced unfortuantly u gotta goto to the dealer have diagnostics ran

they are the coil packs

The only thing left would be fuel. Check fuel pressure , replace the fuel filter, and check the injectors(ohm's from 11 to 15) and the injector harness. Mostly on the harness make sure you didnt pinch a wire putting it back together, especially the map and coolant wires.

The P0172 code is a rich code most likely caused by the P0300. The P0300 is a random/multiple cylinder misfire code. Replace the plugs and wires.

http://www.sparkys-answers.com/2008/11/2001-pontiac-grand-am-codes-p0105-p0172.html

means you have multiple misfires (po300) the other codes are lean codes, possiable tune up , bad injector, fuel pump,

Im surprised that didn't fix it. On the Quad4 engine its usually a cracked coil housing.
Have you checked:

• fuel injectors / fuel pressure
• coolant temp sensor
• compression - to check for bad head gasket
• ignition control module
• EGR system - make sure the valve isn't stuck
• crank position sensor.

The crankshaft position system variation compensating values are stored in the PCM non-volatile memory after a learn procedure has been performed. If the actual crankshaft position system variation is not within the crankshaft position system variation compensating values stored in the PCM, DTC P0300 may set.

Replace the coil going to that cylinder, and then replace the valve cover gasket to prevent further oil from getting on the new coil. If it is not the coil, the crank sensor could have gone bad in it.