cat question for prelude

[Frög]

i have a 97 prelude and my cat is alll broken up inside. it rattles. i need a new one but the honda one is expensive. if i get a high flow cat will i fail emissions? i am obd2..

[§treet_§peed]

not necasarily...it is possible to pass if your car runs clean enough...

[Z U L8R]

^^ made a point, if everything else on your car's working fine, after you put the high flow cat on, change the oil, and run some 93 octane, which'll help a little. the only thing is your rear o2 sensor. it's not uncommon for them to get contaminated when the cat starts coming apart #1, #2 you won't pass if your check eng light's on regardless, #3 if your rear o2 sensor's bung is on your cat like ON your cat, you'll have to weld in a bung for it after the high flow etc etc. changing your oil will help with hydro carbons ( hc % ) like 40-50 parts per million nothing fantastic but it does help :P