Micro-Cats, Catless Downpipes, and CEL

[falsalem]

I want to install catless downpipes...only if I can avoid CEL. So I called Supersprint in the UK to inquire about the Micro-Cat and catless down pipe combo they offer.

Supersprint said a Client installed catless downpipes and got a CEL. Then the Client added Micro-Cats to his downpipes and so far, CEL is gone.

Is that Client on this forum ? I'm hoping to get some good advise on this topic.

Cheers

[Andym3100k]

Originally Posted by falsalem

I want to install catless downpipes...only if I can avoid CEL. So I called Supersprint in the UK to inquire about the Micro-Cat and catless down pipe combo they offer.

Supersprint said a Client installed catless downpipes and got a CEL. Then the Client added Micro-Cats to his downpipes and so far, CEL is gone.

Is that Client on this forum ? I'm hoping to get some good advise on this topic.

Cheers

My friend got SS DP with mico cats, NO CEL.

I got the stock DP & when i remove the ceramic cat I got the CEL light on the 3rd day.

Thereafter I install mico cats on the existing bud n the CEL is gone, is already more than 2mths so don't think is coming back.

[JPMD]

Originally Posted by Andym3100k

My friend got SS DP with mico cats, NO CEL.

I got the stock DP & when i remove the ceramic cat I got the CEL light on the 3rd day.

Thereafter I install mico cats on the existing bud n the CEL is gone, is already more than 2mths so don't think is coming back.

Are the Downpipes with microcats direct from supersprint or placed afterwards?

[Northern X5M]

I have the SS catless DPs with the 200 cell race cats in the mid pipes and with the micro cats I still get a CEL.

[Andym3100k]

Originally Posted by JPMD

Are the Downpipes with microcats direct from supersprint or placed afterwards?

According to him is directly from SS.

[Andym3100k]

Originally Posted by Northern X5M

I have the SS catless DPs with the 200 cell race cats in the mid pipes and with the micro cats I still get a CEL.

My friend didn't have the CEL as mention.

U mean u hv 200 cell race cats in the mid pipe? Is yrs a m5 or a X5m?

[gmd2003]

Originally Posted by Andym3100k

My friend didn't have the CEL as mention.

U mean u hv 200 cell race cats in the mid pipe? Is yrs a m5 or a X5m?

US cars will have a CEL with catless DP's with and without Micro cats . The CEL will be different for each though . Without microcats the ECU will give a catylzer inefficiency code ( thinks the cats have failed due to extra fuel sensed ) . With microcats they will show a secondary O2 sensor lean to rich code ( initially sees normal levels then rich as the microcat is overcome with fuel ) . The US ECU 's are just to damn picky because of California emissions and everything has to be 50 state legal here . I have SS catted DP's with microcats and have the latter code .

[Northern X5M]

Originally Posted by Andym3100k

My friend didn't have the CEL as mention.

U mean u hv 200 cell race cats in the mid pipe? Is yrs a m5 or a X5m?

M5

[falsalem]

Originally Posted by gmd2003

US cars will have a CEL with catless DP's with and without Micro cats . The CEL will be different for each though . Without microcats the ECU will give a catylzer inefficiency code ( thinks the cats have failed due to extra fuel sensed ) . With microcats they will show a secondary O2 sensor lean to rich code ( initially sees normal levels then rich as the microcat is overcome with fuel ) . The US ECU 's are just to damn picky because of California emissions and everything has to be 50 state legal here . I have SS catted DP's with microcats and have the latter code .

Excellent explanation thanks.

New question: I bought my F10 M5 from the US and have shipped it to Kuwait. Can I install OEM BMW European software at the dealership and overcome the over-sensitive US ECU issue ?

[Boss330]

You should talk with Leib Engineering in Germany.

They have cracked the DME and can make custom software, delete CEL, remove speed limiter etc...


More info here:
http://f10.m5post.com/forums/showthread.php?t=1019376