[kini62]

New member, just picked up a low mile 2020 X4 M40i. About the only thing I want to do at this time is a high flow catted downpipe.

Do all the lower cost (20 cell/inch/square) generate a CEL? Or is it a luck of the draw of it will/won't?

Seems there is only one that has the same cell density as stock that guaranteed not to generate a CEL, but it's $1500 (Active Autowerke).

Those that have the cheaper version and get the CEL, is there a way to permanently get rid of it?

Thanks

[suby01]

Cell will happen on all except AA.
Then either live with the light or you need a tune like MHD or BM3 to clear out the CEL.

[Rottweiler]

Depending on your 2020 production date you MIGHT NOT need to send your DME off to Helsinki to get it unlocked to upload a proper tune

Someone here will know that particular cutoff date but you’re likely close

[jayshaaawn]

Originally Posted by Rottweiler

Depending on your 2020 production date you MIGHT NOT need to send your DME off to Helsinki to get it unlocked to upload a proper tune

Someone here will know that particular cutoff date but you’re likely close

I think its like 06/2020.

[biz77]

Originally Posted by kini62

New member, just picked up a low mile 2020 X4 M40i. About the only thing I want to do at this time is a high flow catted downpipe.

Do all the lower cost (20 cell/inch/square) generate a CEL? Or is it a luck of the draw of it will/won't?

Seems there is only one that has the same cell density as stock that guaranteed not to generate a CEL, but it's $1500 (Active Autowerke).

Those that have the cheaper version and get the CEL, is there a way to permanently get rid of it?

Thanks

I too am on the hunt for a DP for my 2021 X3 M40i. 200 cell seems to be luck of the draw, but it seems most will have the dreaded CEL pop up at least intermittently, if not consistently without a tune with a 200 cell DP.
As far as 400 cell DP's go, there is also MST: https://www.mst-performance.com/products/bw-5809dp
and possibly Racing Dynamics: https://www.racdyn-usa.com/PROD/130+10+58+170.html
While they don't specify fitment on the G01, other products do crossover between the G05/G06 and G01/G02 B58's.

Originally Posted by Rottweiler

Depending on your 2020 production date you MIGHT NOT need to send your DME off to Helsinki to get it unlocked to upload a proper tune

Someone here will know that particular cutoff date but you’re likely close

Cutoff for FEMTO unlock is 6/2020. If your DME has a production date prior to this, you can do a simple bench unlock in the states, which typically runs about $250. Easiest way to check this is buy the OBDII adapter and download the MHD app. It will tell you if yours needs a FEMTO unlock for zero out-of-pocket expense beyond the OBD adapter. The next easiest way is to get under your hood and pull the DME up just enough to see the production date on the sticker.

[kini62]

Thanks all. Probably just save up for the AA version.

Love the car so far.

[Rottweiler]

https://www.bimmerpost.com/forums/sh...php?p=31039519

Get this and then do a tune w/ the money you save

[E92M3GT]

On my X3 M40i LCi I have CG Precision DS-1 catted downpipe

Perfect sound, cheaper than AA and no CEL!

https://www.youtube.com/shorts/x9S2MGcNmzQ

[kini62]

Originally Posted by E92M3GT

On my X3 M40i LCi I have CG Precision DS-1 catted downpipe

Perfect sound, cheaper than AA and no CEL!

https://www.youtube.com/shorts/x9S2MGcNmzQ

Thanks. Seems the 200 cell units are hit or miss when it comes to generating a CEL. If they guarantee no CEL at time of purchase it would be worth it over the less expensive 200 cell units. But they probably can't make that guarantee.

As for the previous post, no desire to go for a tune. At most it would just be some type of piggyback module.

[WHITEUNDERARM]

Here’s a link to the sound of my decatted downpipe… Decatted X3 M40i

[umbear15]

I have a 2021 X3 M40i and got the Apex Built catted downpipe. It is a 400 cell GESI that is guaranteed to not cause a CEL. Purchased it a year ago for $1,100. It also cost $1,250 to get it installed by a professional shop. I’m still not sure if I overpaid.

HOWEVER, do not buy it. I get a CEL once a month or so, more frequently during the summer months. It is always the same; low cat efficiency. If I clear the code and drive it slow, the emissions test will pass (all green check marks). If I rev it to redline though, it will fail emissions. The CEL comes on after I push it for a few days, but at least I can pass emissions when needed.

I contacted Apex Built a few times, but they are not responding to my emails. Even contacted the CEO directly via email. No luck. They seem to be refusing to honor their “guarantee.” Avoid them at all costs. Definitely try AA.

Here is how it sounds, even got rid of the resonator.

[Rottweiler]

Originally Posted by umbear15

It also cost $1,250 to get it installed by a professional shop

I’m waiting for the responses to this detail

Some members here are going to be 2b below…

https://www.merriam-webster.com/dictionary/apoplectic

[Burr001]

Originally Posted by umbear15

I have a 2021 X3 M40i and got the Apex Built catted downpipe. It is a 400 cell GESI that is guaranteed to not cause a CEL. Purchased it a year ago for $1,100. It also cost $1,250 to get it installed by a professional shop. I’m still not sure if I overpaid.

HOWEVER, do not buy it. I get a CEL once a month or so, more frequently during the summer months. It is always the same; low cat efficiency. If I clear the code and drive it slow, the emissions test will pass (all green check marks). If I rev it to redline though, it will fail emissions. The CEL comes on after I push it for a few days, but at least I can pass emissions when needed.

I contacted Apex Built a few times, but they are not responding to my emails. Even contacted the CEO directly via email. No luck. They seem to be refusing to honor their “guarantee.” Avoid them at all costs. Definitely try AA.

Here is how it sounds, even got rid of the resonator. https://m.youtube.com/watch?v=ItVPSqRoxQ4

Bro you paid 1250 just to have it installed?...man I have a slightly used bridge for sale, it only got a couple of scratches it's located near Baltimore.

[kini62]

Originally Posted by umbear15

I have a 2021 X3 M40i and got the Apex Built catted downpipe. It is a 400 cell GESI that is guaranteed to not cause a CEL. Purchased it a year ago for $1,100. It also cost $1,250 to get it installed by a professional shop. I’m still not sure if I overpaid.

HOWEVER, do not buy it. I get a CEL once a month or so, more frequently during the summer months. It is always the same; low cat efficiency. If I clear the code and drive it slow, the emissions test will pass (all green check marks). If I rev it to redline though, it will fail emissions. The CEL comes on after I push it for a few days, but at least I can pass emissions when needed.

I contacted Apex Built a few times, but they are not responding to my emails. Even contacted the CEO directly via email. No luck. They seem to be refusing to honor their “guarantee.” Avoid them at all costs. Definitely try AA.

Sound is great.

As for the install it seems like even a DYI only takes an hour even without a lift.

[svic628]

So if you have a 06/2020 production date do you need to ship for unlock? Or youre ok with 06/2020?

[Leem40i]

Unless you have a tune, not a piggyback, getting any DP is pointless and actually results in less power in the usable range. With a tune they can actually dial back in power using the higher exhaust flow and mitigate any CEL's.
If you're going to spend money use it on things that actually add performance.

[Leem40i]

"It also cost $1,250 to get it installed by a professional shop. I’m still not sure if I overpaid."

Let me settle that for you. Yes, you way overpaid.

My last car had two cats and they were a PITA to get out. Cost me $500 for a reputable shop to do the swap.

[Leem40i]

"It also cost $1,250 to get it installed by a professional shop. I’m still not sure if I overpaid."

Let me settle that for you. Yes, you way overpaid.

My last car had two cats and they were a PITA to get out. Cost me $500 for a reputable shop to do the swap.

[kini62]

Originally Posted by Leem40i

Unless you have a tune, not a piggyback, getting any DP is pointless and actually results in less power in the usable range. With a tune they can actually dial back in power using the higher exhaust flow and mitigate any CEL's.
If you're going to spend money use it on things that actually add performance.

First I've heard of this.

[Leem40i]

Originally Posted by kini62

First I've heard of this.

Modern cars are limited by torque to their Factory spec. No matter what bolt ons you put on the car is going to keep its torque ratings in the range of its spec. The only Pace you normally see any gain without a tune is on the top end which is pretty much unusable under normal driving. 9 out of 10 people that get these things without a tune typically just want it so they can say they modded and improve the sound. In a turbocharged car you will get way more gains with just the tune then if you had every bolt on available dropped on with the factory tune. Once you get a tune from a reputable tuner it can be modified to adapt to the new bolt ons and then you'll get even more horsepower and torque.

[kini62]

Originally Posted by Leem40i

Modern cars are limited by torque to their Factory spec. No matter what bolt ons you put on the car is going to keep its torque ratings in the range of its spec. The only Pace you normally see any gain without a tune is on the top end which is pretty much unusable under normal driving. 9 out of 10 people that get these things without a tune typically just want it so they can say they modded and improve the sound. In a turbocharged car you will get way more gains with just the tune then if you had every bolt on available dropped on with the factory tune. Once you get a tune from a reputable tuner it can be modified to adapt to the new bolt ons and then you'll get even more horsepower and torque.

Can you recommend a CAT back exhaust that is less expensive than the AA catted down pipe that will give me similar sound? I don't care about a performance boost, just some sounds.

[Leem40i]

Originally Posted by kini62

Can you recommend a CAT back exhaust that is less expensive than the AA catted down pipe that will give me similar sound? I don't care about a performance boost, just some sounds.

I am not sure about the cat backs that are available but you're on the right track. You'll be able to get a much better sound without the threat of warranty issues. I'm looking at these options as well and I would not consider any Cat-Back unless it also Incorporated the exhaust valves. I wish borla made a system for this car because I have used their exhaust many times in the past and they always make a wonderful deep tone without any drone or raspiness