on the high way was doing 55 and had a straight away gunned it to like 4500 rpm cruised 130 for bout a minute then started smelling a burning sort of smell not like paper burning or oil like exhaust maybe? could it be the o2`s?

 

oh yeah that slp lid really sux it in too, when i popped the hood this morning there was like little twigs and road salt all around the lid and rad support

 

so what did it smell like? could be at that speed you were getting some exhaust sucking in from the back. maybe have a look at your hatch seal and see how it looks. also could be the exhaust has not been that hot in a long while and was burning off road crudd.

 

the hatch seal looks brand new, and the hatch was completely closed, it wasnt totally like rotten eggs but maybe rotten eggs/gasoline. it definitly smelled like exhaust but not normal exhaust. its hard to describe

 

if the car lets say running rich or lean, how would it smell?

 

ahhh well it sounds like the cat was compaining. if you have cat it may have burned some build up from its inside or could be starting to fail.

 

the only way to know if it fails is by the hissing only??

 

no thats one way it can show its ugly head. sometimes they go to pieces and rattle, sometimes they will get red hot and stink, and sometimes it cloggs up and hisses or makes it run craby or just kills the motor.

 

kill the motor???!!!! are they easy to swap (backyard job) or better to take it to a muffler shop

 

well,,, it can cause it to die from not being able to get exhaust gases out of the combustion chamber.
depends on if someone welded one in. have a look and see if itll come off easily. if allowed in your state you can get a high flow cat.