[DravitM4]

Hi everyone,

I have a 22’ M4CX with MST CAI and R44 Catless DP installed. I am running the R44 Catless DP with Big Daddies Mini-Cat spacers.

The CEL comes on for days, then goes away for a day or two and then comes back on. I’m not worried about the CEL, but I am more worried about if the catless dp might cause an issue to the engine? The code I get is something about running to rich or too lean. Is that something I should be worried about?

Thank you!

[TopJimmy]

It’s the upper O2 sensors that control AFR. Those haven’t been messed with.

The lower O2 sensors detect catalytic heat up and health. If you’re catless then a lower O2 CEL means nothing. Ignore it.

I guess your cat spacer needed a hair more space.

[mike@x-ph.com]

Running catless won't cause any issues to the engine.

[Info@mad-us.com]

Like others have said if it's just the lower o2's throwing a code for emissions it's not a huge deal. If possible try and read the codes to be sure it's that and not something else. You may also want to know if it's just one bank or both banks. If it's one bank you may have a cracked cat in the o2 spacer and its easily fixed with a new spacer.

[DravitM4]

Thank you all! Appreciate all the info, I’ll try to throw on some crush washers and see if that solves the problem. 🤗🤗

[mike@x-ph.com]

Originally Posted by DravitM4

Thank you all! Appreciate all the info, I’ll try to throw on some crush washers and see if that solves the problem. 🤗🤗

[Info@mad-us.com]

Originally Posted by DravitM4

Thank you all! Appreciate all the info, I’ll try to throw on some crush washers and see if that solves the problem. 🤗🤗

Try and read the codes before if possible. You can grab a cheap maxiscan off amazon for like 30 bucks.

[DravitM4]

Originally Posted by Info@mad-us.com

Try and read the codes before if possible. You can grab a cheap maxiscan off amazon for like 30 bucks.

This is what it says

[Needsdecaf]

You need to look up the actual code:

"When an OBD-II equipped vehicle has a stored P014B code, it means that the powertrain control module (PCM) has detected a delayed response time from the downstream (or post catalytic converter) oxygen (O2) sensor or circuit for engine bank two. Bank 2 specifies the bank of the engine which does not contain the #1 cylinder.

Read more at: https://www.obd-codes.com/p014b
Copyright OBD-Codes.com"

In this case, seems very logical to get this fault if you are running with no cats.

[racinghart03]

Originally Posted by DravitM4

Hi everyone,

I have a 22’ M4CX with MST CAI and R44 Catless DP installed. I am running the R44 Catless DP with Big Daddies Mini-Cat spacers.

The CEL comes on for days, then goes away for a day or two and then comes back on. I’m not worried about the CEL, but I am more worried about if the catless dp might cause an issue to the engine? The code I get is something about running to rich or too lean. Is that something I should be worried about?

Thank you!

Attachment 3263521

While you will not have any real issues as a result from the wonky AF readings, be careful at the dealer. I have an X6MC on catless and opted to keep the cats on my M4C because my X6 was flagged by BMW for having no cats. I deal with the light, spacers did not work, I have a JB4 on both and while the M4C will not have issues, I do get the code for the wastegates on the X6. I just clear it with the app. My wife will keep her cats on her M8C. Just not worth the headaches for me.

[Indo Rider]

Originally Posted by Needsdecaf

You need to look up the actual code:

"When an OBD-II equipped vehicle has a stored P014B code, it means that the powertrain control module (PCM) has detected a delayed response time from the downstream (or post catalytic converter) oxygen (O2) sensor or circuit for engine bank two. Bank 2 specifies the bank of the engine which does not contain the #1 cylinder.

Read more at: https://www.obd-codes.com/p014b
Copyright OBD-Codes.com"

In this case, seems very logical to get this fault if you are running with no cats.

Thanks for that link. So they way I read it, the "delayed response" is really the postcat narrow band "switching style" sensor not switching back and forth across lambda = 1 when (or as fast) as expected based on the precat wideband sensor reading.

So I'm not sure I'd agree that the delayed response codes are expected due to simply not having cats. But maybe expected/likely if using any type of spacer that moves the postcat sensor tip (too far) out of the exhaust flow?

I've seen some people saying that lamba = 1 for the precat sensor is calibrated based on the postcat sensor reading since the postcat sensor should theoretically be more accurate right at lamba = 1. Can't find specific detailed info for s58 to confirm/deny. Wish some real ECU tuners would chime in since maybe they know if that sort of calibration actually exists and if it's disabled when tuning cars with no cats.

[racinghart03]

Originally Posted by Indo Rider

Thanks for that link. So they way I read it, the "delayed response" is really the postcat narrow band "switching style" sensor not switching back and forth across lambda = 1 when (or as fast) as expected based on the precat wideband sensor reading.

So I'm not sure I'd agree that the delayed response codes are expected due to simply not having cats. But maybe expected/likely if using any type of spacer that moves the postcat sensor tip (too far) out of the exhaust flow?

I've seen some people saying that lamba = 1 for the precat sensor is calibrated based on the postcat sensor reading since the postcat sensor should theoretically be more accurate right at lamba = 1. Can't find specific detailed info for s58 to confirm/deny. Wish some real ECU tuners would chime in since maybe they know if that sort of calibration actually exists and if it's disabled when tuning cars with no cats.

X2 Here. I never had the delayed response until I tried the spacers. Why has no one figured out what the voltage drop needs to be to keep the CEL from illuminating and created a cheater harness to plug in and create the required differences? I would have been all over this when I was younger lol. I am just too old and don't care as much.

[evidence]

I tried the BDG minicats and BDG spacers w my 200 cell DPs, both caused the delayed codes. Dropped all spacers and went w OEM direct mounting to the DPs and no CEL. If you're only getting the delayed code, you likely just need to go OEM or the short empty spacers w catless.

[Info@mad-us.com]

Originally Posted by evidence

I tried the BDG minicats and BDG spacers w my 200 cell DPs, both caused the delayed codes. Dropped all spacers and went w OEM direct mounting to the DPs and no CEL. If you're only getting the delayed code, you likely just need to go OEM or the short empty spacers w catless.

You have our downpipes right? How long as it been with no cel?

[evidence]

Originally Posted by Info@mad-us.com

You have our downpipes right? How long as it been with no cel?

Yep MAD 200 cell catted. 10 days w no delayed reaction CEL w the 2nd O2s direct mounted.

BM3 tuned but haven't disabled the "Catalytic Monitors (CEL)", never received the cat efficiency codes. I'm in Phoenix, so environment likely plays into it a bit. Low has been mid 80s here lol.

[Info@mad-us.com]

Originally Posted by evidence

Yep MAD 200 cell catted. 10 days w no delayed reaction CEL w the 2nd O2s direct mounted.

BM3 tuned but haven't disabled the "Catalytic Monitors (CEL)", never received the cat efficiency codes. I'm in Phoenix, so environment likely plays into it a bit. Low has been mid 80s here lol.

Interesting