Anyone able to pass emissions test with headers and all cats deleted?
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Joined: Aug 2009
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C63 AMG
^ I tried this on an M car a few years ago. It's hard as hell to follow unless there is no traffic whatsoever, no stop signs, no red lights, no cops...etc. etc. etc. I went out at 3:00am on three consecutive nights. It didn't do ****. And BTW, my instructions clearly stated not to exceed 60mph or the test would cancel itself. Royal PITA.
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From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
If you have LTHs installed and removed the seconday cats as well, I highly doubt you'll be able to pass the OBD smog test no matter what.
I had "piggies" (OEM exhaist collectors but with gutted pre-cats) on my RS4 and the only way to pass emissions was to weld in a threaded bung and relocate the second O2 / lambda sensor after the main cats, which were clamp-ons and I could remove and replace at the shop with realtively little fuss, then reflash to stock and drive it like that for a few weeks before everythign went back to normal. What made the process a lot easier with the Audi is that all you needed was a $20 CANbus cable and the VAG-COM software that you could obtain from various sources, so you could essentially monitor everthign until it went ready and/or clear the stored error codes just before the test without resetting the readiness monitors.
The ECU expects to see a difference in the exhaust gas composition between the primary and seconday O2 / lambda sensors - so you have to have a catalytic in between. The spacers are useless as they decrease the volume of exhaust gas that goes by but not the actual composition so they really don't work well. While a tune can disable the sensors, what you get in that case instead of CEL is a "not ready", and in your case you'll likely have two so you won't be able to pass if one is all you're alowed (same as in Ontario).
P.S. All of the above in based on my experience with my Audi and in this reagrd I have no actual experience with the C63, but I suspect the emissions system check and readiness operation is very likely the same.
I had "piggies" (OEM exhaist collectors but with gutted pre-cats) on my RS4 and the only way to pass emissions was to weld in a threaded bung and relocate the second O2 / lambda sensor after the main cats, which were clamp-ons and I could remove and replace at the shop with realtively little fuss, then reflash to stock and drive it like that for a few weeks before everythign went back to normal. What made the process a lot easier with the Audi is that all you needed was a $20 CANbus cable and the VAG-COM software that you could obtain from various sources, so you could essentially monitor everthign until it went ready and/or clear the stored error codes just before the test without resetting the readiness monitors.
The ECU expects to see a difference in the exhaust gas composition between the primary and seconday O2 / lambda sensors - so you have to have a catalytic in between. The spacers are useless as they decrease the volume of exhaust gas that goes by but not the actual composition so they really don't work well. While a tune can disable the sensors, what you get in that case instead of CEL is a "not ready", and in your case you'll likely have two so you won't be able to pass if one is all you're alowed (same as in Ontario).
P.S. All of the above in based on my experience with my Audi and in this reagrd I have no actual experience with the C63, but I suspect the emissions system check and readiness operation is very likely the same.
Last edited by Diabolis; Feb 1, 2015 at 01:48 PM.
