Codes are P0300 and P0101

Here is the vehicle, 2003 GMC Sierra pick up truck 1500 4.8 ltr. Yesterday morning truck was running fine, when i went to pass someone, i stepped hard on the accellerator and the engine started to miss fire, and it revved higher than normal before shifting into the next gear ( automatic trans). the check engine light came on. P0300 and P0101 codes present. I reset computer and drove it again, still runs rough and same codes came back. based on reading the forums on this site sounds like converter pluged is this correct,if so can you tell by holding hand over exhaust? thanks for your help

could be, really two ways to check is to check back pressure or to get a scan tool with data and look at the misfire counters and if it shows all one bank like 1,3,5,7 or 2,4,6,8 then good chance one is clogged.