I need an opinion

darriantbird

Registered User
catalytic converter location?

Well I bought the down pipes from tbird88 and some high flow cats from car sound now I don't want to hack up Wynns beautiful pipes so i plan to put the cats at the end of these down pipes(for those who don't know they end at the cross member).I guess my Question is,to all of you learned shade tree mechs is do you guys think I'll pass emissions with them this far back,I haven't even tested for fitament in this location I am still waiting on some hard ware before I start my project. Any opinions would be helpful!
 
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You CAN pass, but I can't say you WILL pass. Catylitic converters work by being heated up by engine exhaust. After reaching an internal operating temp of about 1000*f, the platinum based catylist starts converting the bad stuff into not so bad stuff. So why are the cats placed so close to the motor right up under the floor? The farther exhaust gas travels, the more heat it loses. Simple. Place the cats as close as possible so they heat up quickest doing their jog sooner. EPA emissions regulations check not only running emissions, but start up emissions before the cats heat up and start doing their job.
If I were you and were bent of placing the cats so far away, I'd wrap the down tubes in at least one layer of header tape to keep the heat in. Less heat loss means more heat gets to the cats and they start to work sooner. Plus, being that far away, they may never get to operating temp to begin with. To be safe, you may want to go 2 layers.
When you go for emissions, make sure your car is good an hot. That will ensure your cats are already up to temp and be working properly when the sniffer is stuck up your pipe. And make sure you don't have to sit for any period of time. The longer your car sits, the cooler the cats will be, then the longer it will take to get them back up to temp, then the better chance you will fail.
Tip #3-make real good friends with your emissions guy.
 
Ok thats funny!

I have been known to bring Dunkin donuts coffee to the emissions guy I go to but... I guess what I am really asking is if any one has a similar set up and passed their test?
 
I would'nt mount them that far back myself, if youre gonna do that you might as well leave them out because there not gonna work for **** way back there.:)
 
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