I think my catalytic converter is clogged i heard they can get pluged with bulid up inside. my car sputters and check engine light is on but i checked the engine and everything looks fine to me my cat is making a sputtering sound and my exhaust is to so i figure i need a new cat is there a way to unclogg it or do i need to get a new one

 

Clogged cats will not trigger a check engine light. you need to check the ecu codes..

Instructions---> http://forums.maxima.org/3rd-generat...-then-off.html

 

your descrption sounds more like a miss than a clogged cat.
a clogged cat will usually cause a severe power loss at speed

 

check injectors
plugs
wires(VG)
coils(VE)
maf
coolant temp sensor
02 sensor
other sensors

and maybe vac leaks