2003 chevy blazer p0300 145000

What is your question?

Idling rough loud very loud while driving kinda chugs to get up to speed shifting at higher than normal rpms. I know there's a hole on the y pipe before the catalytic converter. But thts been there since i got the vehicle (own vehicle for 2 months now wasnt so loud till recently) i do plan on fixing but trying hardest not to yet since the cost. AutoZone told me the fuel injectors but that's almost the same price

What makes this problem better or worse?

Gets louder going up to speed (too much pressure on pedal makes it surge up to speed)hesitates to shift in all gears not horribly

How long has your 2003 Chevrolet Blazer had this problem?

2-3 weeks