[aardate]

I also have the akra DP with the mppsk. I installed the Akra DP myself on the stock exhaust and had zero issues and no CEL. 5 months later I installed the MPPSK at the BMW dealership and had zero issues after as well.

Looks like something went wrong during installation.

It's sucks that you are running into issues I hope you get it sorted out soon as the combination of the akra and mppsk makes this car pretty special in my opinion.

[Hein Jockins]

Originally Posted by aardate

I also have the akra DP with the mppsk. I installed the Akra DP myself on the stock exhaust and had zero issues and no CEL. 5 months later I installed the MPPSK at the BMW dealership and had zero issues after as well.

Looks like something went wrong during installation.

It's sucks that you are running into issues I hope you get it sorted out soon as the combination of the akra and mppsk makes this car pretty special in my opinion.

This is helpful to know. CEL cleared itself last night and didn't come back on today. Not sure what's going on, but considering what everyone is saying here, I'm going to get it looked at by someone who knows more than me. I'll keep this thread updated.

No response from Akrapovic yet addressing potential cel.

[Hein Jockins]

Akrapovic sales support rep responded and reiterated what is on their site regarding this downpipe: "When installing the Akrapovič downpipe, remapping the ECU is mandatory in order to prevent potential “check engine light” warning signals."

Not much help, so I'll update when I get my car on a lift and can see if there was an issue with install or faulty o2 sensor, etc.

Thanks for the help from everyone above.

[dmanb2b]

Yeah that sucks

[Skyhigh]

@Hein Jockins

Did you get to the bottom of this?

[Hein Jockins]

Originally Posted by Skyhigh

@Hein Jockins

Did you get to the bottom of this?

Not necessarily.. My CEL came on for the 2nd time for about a day, and it hasn't returned since then--which would be almost 1.5-2 weeks now. I decided not to take it anywhere cause the expertise for BMW's, tuning, etc. lacks in my area and without a CEL I doubt anyone would know.

I brushed this off initially cause it didn't sound right, but I did speak to one tech when the light first came on to read the code for me-- he said it could possibly be my ECU or MPPSK tune "getting used" to the higher flow. I'm thinking maybe there's some truth to this, and perhaps the DP is indeed emissions compliant/NO CEL.... or of course, the light will come back on in a week or two, and I'll be back here again.

[Skyhigh]

Sounds like BS theory to me, but of course I wish you to never see that CEL again, ever!

[Hein Jockins]

Yeah I have my doubts about the theory, but it at least optimistically explains why it went away and hopefully never returns.

I'll continue to update the thread if/when I learn anything new, as maybe this could help the next poor chap.

[G.Newt]

Originally Posted by Skyhigh

Sounds like BS theory to me, but of course I wish you to never see that CEL again, ever!

The theory might be BS, but that's what happened to me with my CG high flow cat. I had it on for 1.5 years on stock tune, no CEL. I tune with BM3 and get a CEL after a day. I cleared it and it hasn't returned since in the past 2.5 years. I'm hoping that's the case with OP.

[Hein Jockins]

I spoke it's name, and the CEL returned... Kind of glad cause this gives me a reason to take it somewhere and know for sure if its an 02 sensor or something else. Will update beginning of next week when I get it checked out.

[Hein Jockins]

Brought my car to a local performance shop to get my Downpipe/Cat/CEL checked. They removed the downpipe, inspected the cat--all looked good. They replaced one o2 sensor (the one that would cause CEL for cat emissions I think the front sensor?). According to the tech, the sensor was functioning, but when tested, some of the numbers "didn't look right." He said this might explain why the CEL would clear itself after a day and return a week later.

The downpipe inspection wasn't cheap, so I'm hoping there was something wrong with that now-replaced o2 sensor. Besides this, my only other option is to buy another Akrapovic DP, which I'm probably not going to do when everything looks fine with it.

[BMWILUVU]

Originally Posted by Hein Jockins

Brought my car to a local performance shop to get my Downpipe/Cat/CEL checked. They removed the downpipe, inspected the cat--all looked good. They replaced one o2 sensor (the one that would cause CEL for cat emissions I think the front sensor?). According to the tech, the sensor was functioning, but when tested, some of the numbers "didn't look right." He said this might explain why the CEL would clear itself after a day and return a week later.

The downpipe inspection wasn't cheap, so I'm hoping there was something wrong with that now-replaced o2 sensor. Besides this, my only other option is to buy another Akrapovic DP, which I'm probably not going to do when everything looks fine with it.

That would be the rear O2 sensor. What code exactly were you getting BTW.

[Skyhigh]

Originally Posted by Hein Jockins

Brought my car to a local performance shop to get my Downpipe/Cat/CEL checked. They removed the downpipe, inspected the cat--all looked good. They replaced one o2 sensor (the one that would cause CEL for cat emissions I think the front sensor?). According to the tech, the sensor was functioning, but when tested, some of the numbers "didn't look right." He said this might explain why the CEL would clear itself after a day and return a week later.

The downpipe inspection wasn't cheap, so I'm hoping there was something wrong with that now-replaced o2 sensor. Besides this, my only other option is to buy another Akrapovic DP, which I'm probably not going to do when everything looks fine with it.

Rear sensor.

Fingers crossed! Please keep us posted.

[dmanb2b]

Originally Posted by Hein Jockins

The downpipe inspection wasn't cheap, so I'm hoping there was something wrong with that now-replaced o2 sensor. Besides this, my only other option is to buy another Akrapovic DP, which I'm probably not going to do when everything looks fine with it.

Sell it and buy an AA catted dp, maybe able to even put some $ in your pocket.

[Hein Jockins]

Originally Posted by BMWILUVU

That would be the rear O2 sensor. What code exactly were you getting BTW.

It was a fault for the catalytic converter. I'm not sure of the code # though cause I don't have a reader myself.

[Hein Jockins]

I could buy another one, but despite it occasionally throwing codes, it's awesome as mentioned before in this thread. My only concern with it throwing a fault is the ecu might adapt to reduce flow on its own which at that point would negate any value in having a high flow dp. I'm not sure if the ecu works like this, but also once I flash tune, if the ecu works like this it would correct it to allow for higher flow.

And to be honest, even though the tech wasn't 100% confident the replacement of the o2 sensor was the issue, it's the most logical point to start so maybe it's all fixed now.

[Skyhigh]

No, it doesn't (work like that).
A failure to meet emissions is a failure to meet emissions. Nothing the engine can do about it. There is nothing to adjust. The car tells you you are environmentally unfriendly and you will fail technical inspection.
That's all. Annoying but that's all.

[Hein Jockins]

Fortunately for me (not sure about everyone else), I live in a state where no one cares about emissions, so there's no Inspection. Mainly annoying I spent time researching a high flow cat, went with this, and have to deal with faults.

Good to know the ecu doesn't auto-correct this cause that was the only potential "tangible" externality besides a yellow light on the dash.

All that said, I'm assuming it's a faulty o2 sensor and I'm good to go! Until proven wrong that is.. Gonna wait a few weeks to tune so I can look for potential cel.

[Skyhigh]

In my home country people (especially taxi drivers) drive with the freaking yellow light on the dash (almost always because of failed emissions) all the time… for years.
I hate seeing errors and yellow/red lights so I couldn't tolerate it, but they do.

[Hein Jockins]

After the rear o2 sensor was replaced, CEL has returned after a few days. At this point, I give up-- there are no emissions checks in my state as of now, so I can't justify buying a replacement just to see if it clears the fault. I hate to hear about the others in this thread who have had no issues with only MPPSK + Akra DP like me, but it's possible this cat is slightly different than earlier versions.

Akrapovic won't see this as returnable product with a faulty catalytic convertor because their website says these faults are possible regardless of what HJS claims. The Cat/downpipe inspection + new rear o2 sensor was $850 US (yes that seems high to me too), so I'm not gonna bring the downpipe to other shops till I find an answer cause at that point I might as well buy another one.

Time to tune/forget this happened. If I'm not an outlier, please feel free to add to this thread.

[Skyhigh]

That's just sad 😖

[Hein Jockins]

Originally Posted by Skyhigh

That's just sad 😖

Sometimes life is filled with sadness and utter disappointment... Gonna trade my 340 in for a Camry. Unfortunately, I'll probably only cover 1/2 the cost of a 2021 with my CEL on.

I'm kidding. Car sounds sick and drives like a beast. What else can I do.