How to pass inspection with decat/high flows

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Jun 12, 2024 | 08:39 PM

c63intheb

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W205 C63S

How to pass inspection with decat/high flows

Hey all - Time has come to get the car inspected but the car is currently throwing a CEL and the emissions readings are coming back as INC since I have catted downpipes installed. Was planning on installing a 90 degree o2 sensor spacer to the downstream sensor. Has anyone tried this in the past? If so, could you share your experience and how you got it done? Would also like to hear from others on how they are able to pass inspection with decat/high flow cats.Thanks

Jun 13, 2024 | 06:47 AM

OldManAndHisCar

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Joined: Jun 2021

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From: Fleriduh

W212 E63S Wagon - GSL580 - E63 - E350 - C300

You could do what I always did (when I was in Chicago)....title the car in a place with out such ignorant and delusional laws. Or, what I also did was rent (my) exhausts with full cats and what not....I used to rent out 997 Turbo and E46M3 units for folks who needed the moronic sticker.

It is still quite easy to just get Montana plates (or FL plates and on and on and on) and not worry about it.

Jun 13, 2024 | 12:39 PM

Fluffy Nuggets

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Joined: May 2021

Posts: 89

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From: Brooklyn

2018 C43 Coupe

Quote:

Originally Posted by c63intheb

I had 200 cell high flow cats on my c43. I had O2 spacers fitted on the downstream O2 sensors. Putting the car back to stock and driving it for approximately 50-100 miles got all the monitors ready for state inspection.

Jun 13, 2024 | 01:17 PM

c63intheb

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W205 C63S

Hi Thanks for the response. Did you use a 90 degree or a straight spacer? Did the spacer have a mini cat? Could you possibly link the spacer that you had used?

Jun 13, 2024 | 05:24 PM

Fluffy Nuggets

Member

Joined: May 2021

Posts: 89

Likes: 18

From: Brooklyn

2018 C43 Coupe

Quote:

Originally Posted by c63intheb

Hi Thanks for the response. Did you use a 90 degree or a straight spacer? Did the spacer have a mini cat? Could you possibly link the spacer that you had used?

It was a J spacer which is basically a 90 degree one. didn't have a mini cat but it had a metal cylinder to put inside the spacer to trick the air flow for the sensor. Don't have a link but I will put a screenshot of what it looked like. Not sure if they will fit as I used these for a c43. cant remember the clearance when installing downpipes on the c63s but I would imagine they fit.