P0420 P0430 error code

[ekk]

Hi guys, I drive a 2017 M3 CP with below mods:
Miltek downpipes
Akropovic evolution system
Arma intake
ER charge pipe
Alpine stage 2+ tune

I have been getting the P0420 and P0430 error codes, catalyst system efficiency below threshold bank 1 and bank 2.
Sometimes after a few hard pulls, sometimes it just came up whenever it wants to.
I get this once every 2 weeks averagely.
Anyone knows what is the issue? Thanks a lot

[G4BR13L]

A slight deviation in the oxygen sensors is enough to throw a CEL. Are the downpipes catted? There are threads of drivers using O2 sensor spacers as a fix but normally only required for the catless DPs afaik.

How much kilometers/miles ago where the downpipes installed? You should be sure that it is caused by the DP’s before ignoring the fault codes.

[satinghostrider]

Did you put in your downpipes after the Stage 2+ tune?
Because if you did, you need to ask Alex to give you an updated file for catless which removes this catalyst converter code because you do not have cats anymore.

[ekk]

Originally Posted by G4BR13L

A slight deviation in the oxygen sensors is enough to throw a CEL. Are the downpipes catted? There are threads of drivers using O2 sensor spacers as a fix but normally only required for the catless DPs afaik.

How much kilometers/miles ago where the downpipes installed? You should be sure that it is caused by the DP’s before ignoring the fault codes.

DP are careless and were installed before stage 2+ tune.

[ekk]

Originally Posted by satinghostrider

Did you put in your downpipes after the Stage 2+ tune?
Because if you did, you need to ask Alex to give you an updated file for catless which removes this catalyst converter code because you do not have cats anymore.

DP was installed way for the tune...annoying.
Will that be something wrong with the DP?

[ekk]

Originally Posted by G4BR13L

A slight deviation in the oxygen sensors is enough to throw a CEL. Are the downpipes catted? There are threads of drivers using O2 sensor spacers as a fix but normally only required for the catless DPs afaik.

How much kilometers/miles ago where the downpipes installed? You should be sure that it is caused by the DP’s before ignoring the fault codes.

Do I still keep the O2 sensor even with catless DP?

[satinghostrider]

Originally Posted by ekk

DP was installed way for the tune...annoying.
Will that be something wrong with the DP?

Did you inform Alex you were running catless? I'd recommend checking with him as it could be you were given the Stage 2+ catted version instead of the catless version.

[satinghostrider]

Originally Posted by ekk

Do I still keep the O2 sensor even with catless DP?

Yes you have to keep the O2 sensors on!

[ekk]

Originally Posted by satinghostrider

Did you inform Alex you were running catless? I'd recommend checking with him as it could be you were given the Stage 2+ catted version instead of the catless version.

I could recall that he did ask me whether the DP was catless or not.
But may flip him an email in regards to this.
Thanks for helping

[satinghostrider]

Originally Posted by ekk

I could recall that he did ask me whether the DP was catless or not.
But may flip him an email in regards to this.
Thanks for helping

No worries Bro. But it could also mean your O2 sensors could be shot during the install of your downpipes. Just get Alex to check your tune to ensure you're running the catless version before checking your O2 sensors. These sensors are pretty sensitive so it could have been damaged as well.