[Steveo]

That’s the JB4 reading the car’s fault codes…

[AKSteve]

So maybe the car is sensing that too much air is flowing through the downpipes, but the CEL isn't coming on because the air coming through is "clean." I've driven the car a bit today and haven't had a repeat of those codes.

[Nicklv_m3]

Originally Posted by AKSteve

So maybe the car is sensing that too much air is flowing through the downpipes, but the CEL isn't coming on because the air coming through is "clean." I've driven the car a bit today and haven't had a repeat of those codes.

More than likely just soft codes.
Typical Cat related codes are P0420 usually. Which throws a CEL.

So I’d say you’re good right now!

[RideFAST]

This is a question for Nicklv_m3, in regards to your valve controller, can you control the valves before startup? Say I want to start the car up in efficient with valves closed (I too plan on going full catback with apexbuilt catted DP), is that possible with your valve controller?

[Nicklv_m3]

Originally Posted by RideFAST

This is a question for Nicklv_m3, in regards to your valve controller, can you control the valves before startup? Say I want to start the car up in efficient with valves closed (I too plan on going full catback with apexbuilt catted DP), is that possible with your valve controller?

I have my VSC2 setup as-
Default: Auto/OEM (so I can keep valves closed on loud cold starts) and control the valves on start up myself.
ON: valves fully open.

I have the controller programmed to my home link buttons also.

So if I wanted a loud start up, I’ll use my M button setting for sport+, start the car and just immediately press my home link button to open valves fully.

[RideFAST]

Originally Posted by Nicklv_m3

I have my VSC2 setup as-
Default: Auto/OEM (so I can keep valves closed on loud cold starts) and control the valves on start up myself.
ON: valves fully open.

I have the controller programmed to my home link buttons also.

So if I wanted a loud start up, I’ll use my M button setting for sport+, start the car and just immediately press my home link button to open valves fully.

Awesome, thanks for the quick reply and helpful insight. Your car sounds phenomenal! Well done with your setup

[Nicklv_m3]

Originally Posted by RideFAST

Awesome, thanks for the quick reply and helpful insight. Your car sounds phenomenal! Well done with your setup

Thanks man! And NP

[AKSteve]

I guess it was only a matter of time before one thing led to another....
But I'm still just getting the same two fault codes about catted downpipes being detected. Nothing else. The car is driving great though. No weird smells and the power is amazing.

[Asmooth0101]

Originally Posted by AKSteve

I guess it was only a matter of time before one thing led to another....
But I'm still just getting the same two fault codes about catted downpipes being detected. Nothing else. The car is driving great though. No weird smells and the power is amazing.

Damn… that didn't take long. Keep us posted on if the light stays on permanently

[Allerum]

Originally Posted by AKSteve

I guess it was only a matter of time before one thing led to another....
But I'm still just getting the same two fault codes about catted downpipes being detected. Nothing else. The car is driving great though. No weird smells and the power is amazing.

You could add a spacer to the 2nd 02 and it might go away. like 30$

[Asmooth0101]

Originally Posted by Allerum

You could add a spacer to the 2nd 02 and it might go away. like 30$

Is that the same as the big daddy thing? Or something different?

[Allerum]

Originally Posted by Asmooth0101

Is that the same as the big daddy thing? Or something different?

https://www.walmart.com/ip/Vibrant-P...ERTS/170667126

So its nothing special, it depends on your space available for what kind of design you can use. Amazon and other sites are getting rid of listing these though, because EPA has a hard-on for anything involving exhaust.

[Nicklv_m3]

Originally Posted by AKSteve

I guess it was only a matter of time before one thing led to another....
But I'm still just getting the same two fault codes about catted downpipes being detected. Nothing else. The car is driving great though. No weird smells and the power is amazing.

Get the bigdaddygarage mini cat spacers. theyre the best.

[Asmooth0101]

Originally Posted by Nicklv_m3

Get the bigdaddygarage mini cat spacers. theyre the best.

This one? http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html

[AKSteve]

Just to point out again, I haven't gotten any P0420, P0430 Error Codes or anything like that. Just these:

180101 catless downpipe detected bank2
180001 catless downpipe detected

Even when the CEL light came on, I still only had just those fault codes. I cleared the CEL and drove around all day today and it didn't come back on again. As long as no damage is being done to my car or the O2 sensors, I don't mind having to clear some fault codes once in a while.

[RideFAST]

Anyone know what cell count the stock cats are?

[BMWM4CX]

Originally Posted by RideFAST

Anyone know what cell count the stock cats are?

Stock are 800cpsi

[Southern]

Just ordered the Apexbuilt catted downpipes. Will report back after installed. FYI you get another 10% discount if you have a Govx affiliation via law enforcement or medical.

https://www.shopapexbuilt.com/collec...-hfc-downpipes

[Asmooth0101]

Originally Posted by Southern

Just ordered the Apexbuilt catted downpipes. Will report back after installed. FYI you get another 10% discount if you have a Govx affiliation via law enforcement or medical.

https://www.shopapexbuilt.com/collections/bmw-g8x-m3-m4-2021/products/g8x-hfc-downpipes

Did you call in to order or did it online and were able to get that discount?

[LifesAnesthesia]

Originally Posted by Nicklv_m3

If you’re going to spend that much, get the same DP’s as me. ApexBuilt 300 Cell GESI Catted Downpipes. No CEL guarantee w/ GESI cats.
Top notch quality and perfect fitment. And $2500 normal cost.
I got mine for $400 off at ECS.

No need to spend $3500-$3800 on DP’s.

with a completely stock setup, how much sound will catted downpipes add?

[Southern]

Originally Posted by Asmooth0101

Did you call in to order or did it online and were able to get that discount?

I logged into Govx to get the discount code, then used the code when ordering online directly through Apexbuilt

[Nicklv_m3]

Originally Posted by Southern

Just ordered the Apexbuilt catted downpipes. Will report back after installed. FYI you get another 10% discount if you have a Govx affiliation via law enforcement or medical.

https://www.shopapexbuilt.com/collec...-hfc-downpipes

Think I’m one of the first few to have these installed already. Unless someone else out there has them.

They been on my car for over a week so far now and very happy so far.