2000 tahoe 5.3l gives p0300 and p0300 pd trouble codes I replaced fuel filter, the EGR valve, and the EVAP purge solenoid to no evail it still idles rough. What could it be pcv seems to be clear I tested fuel pressure it stays between 46-48 psi. I look forward to any ideas already spent two hundred in parts can't spend much more help

 

have you tried a tune up i had the same problem with my firebird, then got a tune up and ran fine after that.

 

give this a try....

http://ww2.justanswer.com/uploads/Bl...e_cleaning.pdf

 

Thanks nsthegodfather5 tune up fixed it, someone had also put platnium plugs instead of iridium which is the oe plug but runs like normal now. FYI fuel pressure is 42-50psi