i was told that the 5th gens dont have an 02 sensor (i have a 00) I wanna put in a new catalyic converter on my car but need a sensor. What does the sensor do and does anyone kno where i can get a hi flow cat converter? I like the one on custommaxima.com but am looking for a better price. Also is it ok to put a hi flow cat converter on your stock exhaust system? Thanks

 

if you have a fed spec 00 then you have 3 o2 sensors. if you have a cali spec 00 then you have 4 o2 sensors. a hi flow cat on a stock exhaust is not going to any noticeable gains. if the cat is clogged or bad then you will regain what was lost but not gain much. if you have an o2 sensor behind the main cat then you are fed spec and that o2 senor's job is to monitor the main cat.
most everyone that i have seen complain about hi flow cats breaking down prematurely. if i were you, i would save up for something that would give more gains. if you referencing the dyno on custommaxima.com for the gains, it is greatly exaggerated. the cat that was replaced must have had 150k miles on it and almost completely clogged up for it gain that much.