RockLobster

iTrader: (7)

Car: S5 N/A

I have an SAFC-II that was Dyno Tuned with the 5th & 6th Ports stuck closed.

I have since remidied the prolem. The auxilary ports now work perfectly. Do I need to have the SAFC-II retuned? Or will the stock ECU adjust to maintain the AFR (relative to what the SAFC is telling it)?

Same question asked a different way. Do 6 port 13B motors with thier aux ports stuck closed run rich throughout that range 3800-8k+ RPM?

My guess is no, because the only tuning that was done was above 5600 rpm all to lean out the mixture though.

RockLobster

iTrader: (7)

Further does the ECU actually use the O2 sensor to adjust mixture in any way or only to monitor the engine?

NZConvertible

No, the increased airflow is measured by the AFM and the ECU acts accordingly. Mixtures will remain about the same.

The O2 sensor is only used during constant-speed, light-load conditions, during which time the ECU will attempt to keep the mixtures a stoichiometric to minimise emissions. At all other times the O2 sensor is ignored.

SureShot

Your low throttle map on the S-AFC can also be leaned from 1500-3000 for some fuel economy.

RockLobster

iTrader: (7)

Thanks, guys! I can say after driving it around last night it sure is a rocket now (for an N/A rotary anyway).