High Flow Catted Dowpipe & Exhaust CEL

[TheBoofersUnion]

Has anyone found a workaround for the p2275 CEL code for a high flow catted downpipe? I had some custom fabrication done a few months back on my 09 Gti (catless downpipe & exhaust) + a stage 2 tune. The CEL went on shortly after the fab work so I tried a spacer, that didn’t work so today I went back and had him install a high flow cat. Not long after driving home the CEL went right back on, my fab guy told me to contact the tuner. Does anyone know if this is something that can be tuned out or am I just screwed forever unable to pass emissions unless I reinstall my stock downpipe every time?

 

[iiCaptain]

To my understanding the CEL can be taken away with a tune, but I don't have emissions here so I can't comment on that part of the question.

 

[drval85]

Some off the shelf tunes get rid of the rear sensor reading, but then you’re guaranteed to fail emissions, at least in NJ. You’d have to re-flash to stock every time to part readiness, which leads you to the same problem. Need to find a working spacer setup. Regardless, you’d fail visual inspection for not having a cat.

 

[BudgetPhoenix]

Check with your tuner but these cars are very picky about the o2 spacers. They will clear the p0420 but you get o2 stuck/lean rich codes. An aftermarket cat wont do anything. Might need to get a specific type of o2 spacer like a vibrant J spacer and play around with the angle and jet size. Try facing it toward the front of the car.

 

[Joe_Mama]

Unitronic deletes the cel fyi

 

[BudgetPhoenix]

Some off the shelf tunes get rid of the rear sensor reading, but then you’re guaranteed to fail emissions, at least in NJ. You’d have to re-flash to stock every time to part readiness, which leads you to the same problem. Need to find a working spacer setup. Regardless, you’d fail visual inspection for not having a cat.

Yeah in Cali I just always flashed back to stock and threw on the OEM downpipe every 2 years. Visual inspection is part of the normal emissions inspection and it's insta fail if they see a non carb approved downpipe.

 

[Thumper]

Some off the shelf tunes get rid of the rear sensor reading, but then you’re guaranteed to fail emissions, at least in NJ. You’d have to re-flash to stock every time to part readiness, which leads you to the same problem. Need to find a working spacer setup. Regardless, you’d fail visual inspection for not having a cat.

This.

You have two issues here, the CEL and emissions. The first is easy, the tuner should be able to code to ignore the CEL.

The second is a mess. Different states handle emissions differently and they seem to change regularly so have to check with your state emissions regulations body. Some states will allow you to have one failed readiness code, some will allow none, some do visuals some just check readiness, some still do sniffer tests, etc. CA is it's only animal of course with their CARB garbage.

Catless there's really no options other than swapping DPs. With a high flow, your options are to swap DP everytime you need an emissions test or play with spacers until you are able to pass readiness for at least a short time needed to get to the emissions place and pass the test. Spacers aren't really a long term solution unless you get really lucky, best thing to do is to get the tune to ignore the CEL for your daily life. Experiment with spacers until it will pass readiness once all codes are cleared. Then you just have to clear codes and set your tune back to the stock file (the tune cancels the CEL by telling the ECU to ignore readiness which means it shows as NOT READY and will fail emissions) and pass the test before the variations from the spacers register with the ECU.

Or the best option as I always say in threads like this..........move.