Fuel System Monitor Dysfunction Exposing the Underlying Causes

If the PCM reads more or less fuel than that the evap monitor WILL NOT start and this has to be done twice with a minimum of an 8 hour cool ... The fuel level being empty, and now full, may have a lot to do with your troubles. Once it gets down to around 3/4 tank, I'd start watching the ... All emissions readiness monitors are set, except the O2 sensor monitor. Both catalyst and O2 heater monitors are set. They won't even test it for emissions ... ... the drive cycle to set the OBDII system to show ready. ... The monitors I could not reset were the Oxygen Sense, Cat Monitor, and EGR system ... Less fuel vaporization at low temps throws off the vapor pressure requirement. In my state TWO monitors can by "not ready" and the OBDII test ... In order to get the OBDII system to set the monitors to "Ready," the vehicle needs to be driven through a drive cycle/drive trace. If you don't ... A lot of OBD readers will have a section that shows a list of monitors that show which ones are ready, which ones are not ready yet, and a few ... Also related to the OBD II system are “Readiness Monitors”. Monitors are not physical devices, but rather programs within the on-board computer(s) that relay to ... ... not ready" state, usually the Evap System, and pass smog. If you have a continuous monitor out of ready, even if it's the only one, you fail. monitors the performance of the ignition, fuel metering and emissions systems, including the ... the correct drive cycle for the monitor that is “not ready” for.