truck emission codes coming up p102 and p300

That is P0102 and P0300... For definition and possible cause go to ...'engine-codes.com'...enter code, click on Chevrolet! ... P102 and P300 aren't valid codes!

P102 is The Mass Airflow Sensor (MAF) The code means that the sensor is sending a low voltage signal to the computer. This will cause misfiring , erratic engine performance etc... Because P300 is a code for engine misfiring, I suggest you do the MAF sensor. This should take care of the reasons for P300 The Mass Airflow Sensor is in the Plastic/rubber duct between the engine & the Air Filter. Usually held in by a clamp at each side HOW TO REPLACE https://www.youtube.com/watch?v=ZDbAwfogMQ0 engine code & explaination http://repairpal.com/obd-II-code-chart