I know this will be somewhat of a loaded question but I'm going to ask anyway for my own planning purposes. I have a 2009 GT/CS that I installed a set of Detroit Rockers on. Ive been searching for months and have seen everything from the cats will die instantly to some guys that have 30k miles with them no issues. I know it depends a lot on driving style and tune but how long will stock cats typically hold out? I started with a BAMA canned tune for the cams and had it dynoed yesterday and I told the guy I wanted emissions safe tune so that's what he gave me. It dynoed 304hp/311tq at the rear on a dyno jet so I'm pretty happy with those results since I'm still running stock air box and only shorty headers. I need to keep cats for emissions (We have visual and OBD2 only). I plan to do long tubes in the future and was wondering if I should keep the stock cats and have them fabbed to fit the long tubes or if something like the kooks green cats would be a good option. Just looking for peoples personal experience running these or similar cams and cats. I have heard good things from the hot rod cam guys running stock cats and these have a milder lope so I would assume less raw fuel being dumped to the cats but would still like to be ready for any repairs in the future. This is a daily driver but mostly sees highway miles. It doesn't see a lot of idle time which seems to be the hardest on the cats.

thanks for any info.

 

Really just curious if I need to stockpile a set of cats in case these fail and if so what brand and metallic or ceramic.

 

i have been running the hot rods with stock cats since 2008, still passes emmissions every time. i would not worry about it, just make sure your tune is good.

 

Awesome thanks for the info! The rotten egg smell is starting to subside I guess the tune is finally setting in. Just like to be prepared. Thanks again.

 

Hammeron who did you tune?

 

Brenspeed supplied my first tune, works great. Since then, I use my own
tune (SCT Advantage III).

 

The cats should be effective for as long as they would with the stock cams... which is about 7-10 years. The dirty secret of the smog ****'s is that a well tuned car CAN pass the actual measured tailpipe emissions without cats, of course if you tamper with the emissions equipment it is a violation of federal law.

 

Yeah j know cats are mostly for the people that run their cars into the ground since they no longer run optimum. Honestly my state isn't that picky but I'd prefer to stay legal I do road trip the car and don't want to get pulled over out of state and have them start poking around. I was thinking long tubes and just reusing stock cats but haven't decided yet. Thanks for the info!