CEL light with sports cat

F36 435i M · 09-27-2021, 11:27 AM

Hi guys,

Just recently had a sports cat installed and when I picked up the car a few days ago there was no CEL and was completely fine. About 50 miles later a CEL has appeared today, the car is a N55 435i 2015. Do I need to get this coded out right away or can I leave this for a while? Been told it’s possible for the car to go into limp mode ? Not sure how true this is. Any advice would be great, thanks again!

Fliplegend · 09-27-2021, 12:39 PM

Wouldn't be surprised if the CEL came on at the shop and they just cleared it and gave you the car back.

thejeremyman9 · 09-27-2021, 01:31 PM

Also tell us what downpipe it is, unless its AA, fabspeed, or CG precision the CEL is expected.

Boostedphil698 · 09-27-2021, 02:52 PM

Piggy backing off thejeremyman9, unless it is AA, Fabspeed or CG, you were doomed to get a CEL from the start. Let us know the brand and we can go from there.

F36 435i M · 09-27-2021, 03:54 PM

Thanks for the replies. Been speaking to Jeremy, just a case of getting it mapped out. Just hoping it doesn’t need doing too soon, shouldn’t be urgent

njdangelo · 09-27-2021, 09:29 PM

My cts turbo catted downpipe has never thrown a CEL

thejeremyman9 · 09-27-2021, 10:12 PM

Quote:

Originally Posted by njdangelo

My cts turbo catted downpipe has never thrown a CEL

Do you have it disabled with the tune?

Does your catalyst emission monitor show as ready?

njdangelo · 09-27-2021, 10:15 PM

Quote:

Originally Posted by thejeremyman9

Quote:

Originally Posted by njdangelo

My cts turbo catted downpipe has never thrown a CEL

Do you have it disabled with the tune?

Does your catalyst emission monitor show as ready?

No and yes. I did purchase an extender in case I ever needed it but it's been fine since install. I know others have experienced different results so I'm wondering what contributes to the CEL in those conditions.
Only thing I can think is a dirty burn. I change my oil every 5k and the plugs are only 15k old so maybe that helps.

thejeremyman9 · 09-28-2021, 12:52 AM

Quote:

Originally Posted by njdangelo

No and yes. I did purchase an extender in case I ever needed it but it's been fine since install. I know others have experienced different results so I'm wondering what contributes to the CEL in those conditions.
Only thing I can think is a dirty burn. I change my oil every 5k and the plugs are only 15k old so maybe that helps.

Interesting, is this a recent purchase? Some DPs go through some iterations. Could also just be variation in cat quality. Also, usually the harder to drive it the more likely it is, since this makes the cat "work harder" than just babying the car so the DME can pick up on small variations vs OEM.

njdangelo · 09-28-2021, 05:32 AM

Quote:

Originally Posted by thejeremyman9

Quote:

Originally Posted by njdangelo

No and yes. I did purchase an extender in case I ever needed it but it's been fine since install. I know others have experienced different results so I'm wondering what contributes to the CEL in those conditions.
Only thing I can think is a dirty burn. I change my oil every 5k and the plugs are only 15k old so maybe that helps.

Interesting, is this a recent purchase? Some DPs go through some iterations. Could also just be variation in cat quality. Also, usually the harder to drive it the more likely it is, since this makes the cat "work harder" than just babying the car so the DME can pick up on small variations vs OEM.

It's been installed for just over a year now and I've done two track days with it

09-27-2021, 11:27 AM	#1
F36 435i M Private 8 Rep 73 Posts Drives: BMW 435i GC Join Date: Jul 2021 Location: Uk iTrader: (0)	CEL light with sports cat Hi guys, Just recently had a sports cat installed and when I picked up the car a few days ago there was no CEL and was completely fine. About 50 miles later a CEL has appeared today, the car is a N55 435i 2015. Do I need to get this coded out right away or can I leave this for a while? Been told it’s possible for the car to go into limp mode ? Not sure how true this is. Any advice would be great, thanks again!
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09-27-2021, 12:39 PM	#2
Fliplegend Captain 1471 Rep 975 Posts Drives: 2015 435ix F33 Join Date: Nov 2018 Location: NH iTrader: (0)	Wouldn't be surprised if the CEL came on at the shop and they just cleared it and gave you the car back. __________________ 15' 435i F33 Metallic Grey/Dakota Black/Contrast Blue \| AWD \| M Sport 15' 328i F30 Mineral White/Dakota Saddle Brown \| AWD \| Luxury Line
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09-27-2021, 01:31 PM	#3
thejeremyman9 Major General 4362 Rep 7,602 Posts Drives: 2015 BMW 335i Join Date: May 2019 Location: Cali iTrader: (0)	Also tell us what downpipe it is, unless its AA, fabspeed, or CG precision the CEL is expected.
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09-27-2021, 02:52 PM	#4
Boostedphil698 Major 436 Rep 1,119 Posts Drives: 2015 BMW 435i Xdrive MSport Join Date: Mar 2020 Location: Greater Philadelphia iTrader: (0) Garage List 2015 BMW 435XI [0.00] 2009 Honda Civic [0.00]	Piggy backing off thejeremyman9, unless it is AA, Fabspeed or CG, you were doomed to get a CEL from the start. Let us know the brand and we can go from there. __________________ 2015 435i Xdrive (Klaus) Stanced 8th Gen Honda Civic (The daily)
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09-27-2021, 03:54 PM	#5
F36 435i M Private 8 Rep 73 Posts Drives: BMW 435i GC Join Date: Jul 2021 Location: Uk iTrader: (0)	Thanks for the replies. Been speaking to Jeremy, just a case of getting it mapped out. Just hoping it doesn’t need doing too soon, shouldn’t be urgent
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09-27-2021, 09:29 PM	#6
njdangelo Captain 436 Rep 844 Posts Drives: 2019 x5 50i Join Date: Sep 2019 Location: CT iTrader: (1)	My cts turbo catted downpipe has never thrown a CEL __________________ 2019 x5 50i - current 2016 340i THP stage 2 - gone but not forgotten.
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