i need help with my stang

my 95 gt has been giving me problems since i had the exhaust put on and a tune up done on it.

problem #1 ive had some sort of slight rattling noise coming from the engine while accelerating but when i finally get to the speed i want and ease off the gas the rattling stops.i can hit the gas and again and it start back as long as the pedal is mashed down.i lift and it stops

problem #2.last night i was driving and all of a sudden there was the most god awful sound coming from my car.i mean it sounds worse than open headers ever thought about being.when i let off the gas it would start to pop slightly.today i let it idle and the left side pipe had normal pressure coming out of it while the right side didnt have hardly any pressure coming out of it.

if anbody can help me out by giving me an idea of whats wrong i'd appreciate it

Blown header gasket.

thanks man.is it the one that goes betweem the cylinder head and the header or the header and the collector.i know it sounds like i dont know much about engines and thats because i dont. im goin to a technical college next year and im gonna take the auto service tech course so i can work on damn near any type of engine

most times it's usualy the one between the header and the cylinder head. it a tick tick tick type sound right?

it was the exhaust pipe rattling against something.the sound i heard when it went out was the pipe blowing to pieces where it was rubbing against something.its fixed now and i havent heard the rattling since.thanks for the help