Originally Posted by fozziebear
All Duratech's had the mani cat from the get go in 04.The cats can flow far more than what these engines can push out.You will not see any consistent or measurable gains by deleting the cats.If you want to get a header then pick up a small Magnaflow universal cat and put it in right after the header flange and relocate the o2 sensors.You will still have a fully functioning cat monitoring with no emissions worries and get the performance boost with the header.
I know where i live every smog shop checks EVERYTHING!!! they look under everything i even had a shop put a car on a lift to make sure cats weren't moved from factory location or o2 location.. the old unplug battery or clear codes right before going doesn't help either they can see if that has been done and u have to drive 40 miles for the computer to go through all its tests again.. sniffer dyno test sniffer idle test evap test timing check obd check all vacuum routing has to be factory its stupid! luckily there is still a few people in town i know that have there own machines and r willing to dirty smog for a 12 pack and 100 so when turbo swap is done don't need to worry about that:) i have seen a few smog stops on the side of the road and as u drive by a peace officer directs u to the portable machine... some peace officers even will have u pop your hood and check stuff out for even a tail light out if he wants to he does if not he sends you to ref anyways...
i believe last year california denied i bill wear 2000 and newer was obd only test but it was denied of course!
im uncertain if we have to have second cat to pass smog though? my car is pzev so idk if i want to risk failing and having to smog every year rather then every 5