Troubleshooting the Enigma Why Your Fuel System Monitor Stays Unready

The " Catalytic, Evap, 2nd Sys, O2 Sensor (both heated & non-heated), and EGR System are all marked as not ready." Those all require specific ... 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 ... I went to have the truck inspected and initially it failed emissions because the NOX/SCR Monitor and Exhaust Gas Sensor were listed as not ready. But normally the evap drive cycle to complete you need more than 1/4 tank of gas but not more than 3/4 tank of gas, it must sit over night, and ... This condition can be achieved by letting the car to sit overnight. The ignition key must not be left ON position before the cold start. if the evap monitor is not ready, verify that your fuel cap is tight and the level of fuel is between 1/4 and 3/4 full. if all the other monitors are ready ... Every vehicle made after 1996 has to have an OBD2 system built in and that system will have various emissions monitors that signify when it ... 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 ... chances are the ecu just did not have enough time to cycle and set the readiness codes. give it more time and try again. Diagnostic scanner? IIRC, these trucks have Misfire, EVAP, O2, Heated O2, Catalyst, Fuel System, EGR/CMP and I can't remember the last monitor.