Aggressive Cam and Emissions

plev72

Registered User
This (I'm hoping) will be a fairly easy question to answer, I am doing/having done a performance rebuild. Obviously I want to go with a fairly aggressive Cam. I live in Arizona and do have to pass emissions. I currently have the 3rd Cat deleted, but am running with the other 2 cats. If I go with a very aggressive Cam I've been told that I may have problems passing emissions. I have the MN12 Chip-Tuner. Is it possible to "detune" the car for purposes of passing emissions via the tuner?

Thanks,
Paul
 
There are a lot of tricks to passing smog. I have a huge cam and my car isn't registered right now because of it. I should have it able to pass now though, I will know Friday. Theoretically if you burn everything that goes in there won't be much coming out but the problem is when you get a big cam at idle it loads up and doesn't burn all the fuel. If you can get it tuned to burn all that fuel going in then you've got it made. This is what I have done. Add methanol(about 1 gallon to a full tank) before your test. It is a highly oxidized fuel that will help burn everything in your combustion chamber. I also have a calibrator from Pro-M that allows me to lean it out a little before the test. That didn't quite get me to pass but it was close and I didn't have cats in the car at all. This time I am going to bring my dog, maybe he'll help. j/k Seriously, I just put a cat in place of my resonator but have hollowed out the two cats in the stock position. This should be able to get me past the sniffer. I have a huge cam though, doesn't even really pull until 3500. If I would have have those cats on during the test I know I would have passed. So, go with the bigger cam and leave your cats on and you should be fine, if you're still worried then pour the alky in the tank.
 
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