2005 GMC Canyon p0300 p0506

Hey,

I have a 2005 GMC Canyon 2.8l 4 cylinder with 116,000 miles. I have a check engine light on with codes p0300 and p0506, which are random misfire and low rpm codes I believe.

I was wondering if anyone has any suggestions in which direction to go. I am thinking a dirty throttle body possibly, which I will be cleaning when I go back out for a can of cleaner. I looked at stft and it was staying around +3 to -2. I was hoping for a high number so at least I would know to look for a possible vacuum leak or something. The idle jumps up and down around the 500-550 to 600 range. I unplugged the maf sensor to see if it would maybe default to something and get better to possibly tell me if it was dirty or bad?!, but it didn’t help anything. It was showing around 3.5 g/s at idle. The truck seems to run fine when it gets going though as far as I can tell. Any suggestions or anything to look for in the live data that could help are definitely appreciated. Thanks