[Diy_efi] maps that are near perfect

[Michael Richards]

Hi,

Normally an ECU throwing a bad O2 code will default to something sane 
like +5% EGO correction and that's it. +/- 5% is not going to make any 
real different and it's definitely not going to blow your engine! NA 
engines are really difficult to blow up with just mixture. Just engine 
to engine manufacturing differences, ie casting offset on the head can 
make 3-5% flow difference.

-Michael

> What is a near perfect map ?
> 
> Why would the engine fail if the fuel delivery was say 3%
> less than perfect?
> 
> <snip>
>>>> MOST ecu's, when they go to limp mode due to a failed O2
> 
> It's not limp mode. It's simply ignore mode.
> 
> I would never have been able to sign off on a engine mapping
> that had a change of behavior during an O2 fault.
> 
> No point in leaving the check engine light off if the thing is
> going to misbehave and alert the customer.
> 
> There was always the improvement if fuel economy to keep
> them from ever suspecting anything wasn't perfect.

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