HELP! Car sounds like its on TB's & less torque :\

Started my car up friday night to go out and the engine tone seemed slightly different! (you know them ones where you drive the car and you and only you know when theres a problem because it wasn't like it before and when you ask someone if they notice it and they dont, but you do!)

Anyway, i drove it down the road and it seemed slightly louder than usual. The car eventually warmed up and i took it on the motorway and wow! Th thing sounds like its on throttle bodies and it just doesnt seem to have the same pull as it did! I dont know whats happened to it! :\

Cars got louder for some reason and lost torque.

I replaced my exhaust manifold about 3 weeks ago and havent had any problems up until now, cars been running like a beaut. But im thinking it could either be a hole in the exhaust/exhaust leak, or a cracked inlet manifold :\

I dont really know but if anyones heard of a problem like this before please let me know!!

Many thanks, Reece..
 
airbox lid half off?

BTW on a 197 if you take the rear seats out you can hear a lot more and you can hear it popping a little if you blip the throttle!