Error Codes - Help Needed Pls

[tokic_o]

Hi everyone,

So few days ago my 2008 e92 m3 just threw the engine light with Increased Emissions message on my idrive. Scanned the codes and I got the following:

1. 2789 - Catalytic Converter Conversion Bank 1
2. 278A - Catalytic Converter Conversion Bank 2
3. 27B0 - Secondary Air Flow System Flow Rate Bank 1

Anyone had experience or knowledge about these codes? I have been using a Megan Racing axleback for 2 years now and have never replaced or touched my original Cats but I didn't think the Cats would die? Could there be an exhaust or gasket leak?

Any help is greatly appreciated!

[warp10]

Originally Posted by tokic_o

Hi everyone,

So few days ago my 2008 e92 m3 just threw the engine light with Increased Emissions message on my idrive. Scanned the codes and I got the following:

1. 2789 - Catalytic Converter Conversion Bank 1
2. 278A - Catalytic Converter Conversion Bank 2
3. 27B0 - Secondary Air Flow System Flow Rate Bank 1

Anyone had experience or knowledge about these codes? I have been using a Megan Racing axleback for 2 years now and have never replaced or touched my original Cats but I didn't think the Cats would die? Could there be an exhaust or gasket leak?

Any help is greatly appreciated!

Sounds like O2 sensors

[tokic_o]

Wouldn’t there be at least an error code that would mention an O2 sensor if it was? I remember when I had to change an O2 sensor last year the code specifically said which O2 sensor too

[warp10]

Originally Posted by tokic_o

WouldnÂ’t there be at least an error code that would mention an O2 sensor if it was? I remember when I had to change an O2 sensor last year the code specifically said which O2 sensor too

Or your cats have gone bad?

[tokic_o]

No one else had this set of codes pop up before? I'm wondering if it would be the sensors on the cat or the air flow sensor or if the cat is actually gone bad? (car has 86.5K miles never tracked)

[eatsleepboost]

A check engine light is likely caused by 1 code and not 3. I would clear all codes and as soon as the light comes on check to see what it is. That code converted to a P code is P0420. I have changed the cats in many cars for that code and they have never come back. It's a cat Efficiency DTC.

[dpilat8588]

definitely sounds like O2 sensors to me.

[gone b]

Your O2 sensors are out. This happened to my buddy as well. Easy fix!!

[E92M3NYLA]

Originally Posted by tokic_o

No one else had this set of codes pop up before? I'm wondering if it would be the sensors on the cat or the air flow sensor or if the cat is actually gone bad? (car has 86.5K miles never tracked)

I just got the same fault codes. Have you changed your cats, O2 sensors or the air flow sensor?

[tokic_o]

Originally Posted by G35Coupe

I just got the same fault codes. Have you changed your cats, O2 sensors or the air flow sensor?

I ended up changing the air flow sensor and a O2 sensor and its gone.

[waldron80]

Which part is the air flow sensor? The sensor on the SAP hose or the sensor on the plenum?