What is the cause of fuel mode 6 (cat protection?)

[suspect]

Is fuel mode 6 caused by high calculated EGT in which case it uses an alternate cat protection AFR table? Or is the high EGT calculation caused by another problem which then causes fuel mode 6 because EGT is too high? Or is fuel mode 6 caused by anything else?

What would cause high EGT calculation? Running lean? Too much boost? High intake air temp?

 

[carabuser]

Too little timing causes high EGTs. Timing pulls due to knock or traction control will cause it to rise quickly.

 

[suspect]

Too little timing causes high EGTs. Timing pulls due to knock or traction control will cause it to rise quickly.

Thank you. Do you know if fuel mode 6 is selected solely based on exceeding EGT threshold?

 

[carabuser]

Looks like 3 triggers, oil pressure regulation which is not applicable for N54, exhaust temperatures and lambda.

If your EGTs aren't triggering it then maybe you are too lean or rich. Check the fuel floor tables, maybe you're running too rich.

 

[suspect]

Looks like 3 triggers, oil pressure regulation which is not applicable for N54, exhaust temperatures and lambda.

If your EGTs aren't triggering it then maybe you are too lean or rich. Check the fuel floor tables, maybe you're running too rich.

From the logs it looks like EGT is triggering fuel mode 6 every time it goes above 950C.

I have been told oval injector bores or DMF is causing misfires at high rpm. There’s no other indication of a misfire. Would you know if these two issues could potentially contribute towards high EGT calculation? And if there’s something I could try to track it down?

MAF around 470 and AFRs are around 11.9-12.01 just before fuel mode 6 is selected. There are sometimes timing pulls before or after this time but they don’t seem consistent or on same cylinder.

 

[carabuser]

That will be caused by this table:

It's in the public XDF, just increase the values (XDF is in freedom units so that equates to 950°C)

 

[suspect]

That will be caused by this table: View attachment 113192

It's in the public XDF, just increase the values (XDF is in freedom units so that equates to 950°C)

So its nothing to be fussed about? It doesnt indicate oval bores or something else wrong with the engine?

 

[carabuser]

So its nothing to be fussed about? It doesnt indicate oval bores or something else wrong with the engine?

No, you'd get misfires with oval bores

 

[suspect]

No, you'd get misfires with oval bores

Thank you