ECM fault? Marginally GMECM

[CSH-HQ]

Guess what, have you read the archives about how a converter works?.
Do you think the engine runs at a steady 14.7:1 AFR?.
If it ran at 14.7:1 all the time there would be no variance to the O2.
So it must change, OK for what reasons.
Can the ecm be run in open loop at idle?.
Those answers and more in the archives
Grumpy


 Guess what makes no difference. That's why I was asking if the program
>in ECM could be written such that it causes oscillation???
>