Originally posted by TommyBoy:
By the way, when I am not accelerating or decelerating it just bounces back and forth from "rich to lean" !!!whats that all about????
Normal operation of the PCM during "closed loop" mode. The O2's will oscillate above and below 0.45 volts (14.7:1, stoich) when the PCM is being most efficient with fuel (and emissions). Mine range from 0.035 V - near 0.8 V, sometimes more when it's doing this. (My S-AFC gives me the exact voltage digitally.)
The O2's on the car are so imprecise at any value away from 0.45 V that as long as a bunch of lights (green) light up at WOT, you are fine. In my car, if I get more than ~0.91 V I foul spark plugs, but other people can run as high as 0.93 or 0.94 fine. You can't really get anything out of the WOT reading with the OEM sensors.
In reality, it makes the A/F meter more bling than functional gauge, but I still think they look cool and want one eventually.