Originally Posted by Relic1
1 & 3 are considered open loop (all though your CAI has nothing to do with it, it's a value in the ECU that coresponds to a MAP sensor value that determines it.)
but 2 is not really worded right. If you're accelerating hard and let off the throttle a little to cruise the ECU will be in closed loop. If you're accelerating hard or cruising and let off the throttle completely then ECU shuts off the injectors. Not really closed or open loop...
Correct. You should go full lean when completely off-throttle.
While everyone's on the correction kick today
, I thought I'd point out that an a/f gauge doesn't give you info about your a/f ratio. It just tells you how well your o2 sensor is working because it just reads 0-1 volt based on what your o2 sensor smells. It's not accurate.
Your air/fuel ratio is a calculation that determines how much air is in your fuel. Ideally it's supposed to be 14:1, but many engines prefer a different ratio. I run 12:1 for safety reasons and still get knock at 21 PSI. If I could get 100+ octane gas, I'd run a leaner ratio like 14:1 and get much better gas mileage.