Accuracy

[FLAMSP]

I have a wide band AEM 02 gauge. When i start to hit boost 1-3 psi it still reads around 14.5 AFR @ full boost and 3/4 throttle I get 10-11 AFR. I was wondering if narrow band as well as wide band gauges are only accurate a 3/4 throttle??

Alex

[FLAMSP]

ok... should my Wideband 02 gauge show an instant change when i hit boost ex. 1 psi or 6.5 psi.

[livelyjay]

My WBO2 sensor was accurate always. The problem with AEM is there is no data logging capability. The stock MSP ECU doesn't do a very good job with fuel delivery. When you get close to hitting full boost the ECU dumps fuel in and you should see it drop to 9 or 10 AFR. If you look at the following graph, you can see how the ECU responds to throttle. At around 3100rpms I hit full boost and the ECU basically dumps fuel. As you move up the rpm range it should lean out a bit, but not much.

http://www.csh.rit.edu/~jasonoff/pictures/dynographs/20050917/dyno03.jpg