it keeps failing because the obd system readiness results show the catalytic converters, oxygen sensors, EGR systems, and evap systems are "not ready." the car runs great. it gets great mileage. no driveability problems and it passed the sniffer test 2 yrs ago with the budget ypipe. i swapped my stock ypipe and stock ECU in and it fails the new plug-in obd testing. i used to have the Gforce ECU and the budget ypipe for a few years. could that have messed things up for me? i'm wondering if somehow my stock ECU got fried in storage or because i left the CEL on for so many years. i thought about disconnecting the battery overnight in addition to resetting the stock ecu. perhaps i'll try those things before looking at every single one of those systems. one last note: my ecu threw the code 0903 which is the evap purge valve actuator. if all else fails i'll try buying a sticker somewhere.

 

I had the same problem when I was trying to pass emissions. I had for sensors comming up as "not ready." Everyone told me that the only solution was to just drive it. When ever oyu reset your ecu, you need to drive for those sensors to come back on. Usually you only need to drive about 500 miles, but that never happened for me. They ended up comming on about 2k miles and about 6 months later. Just unplug your battery over night, then just start driving it for a while.

 

Fix the evap purge valve actuator, clear the error code and drive the car for a week or two. Make sure it goes through complete cycles, from cold completely up to operating temp several times.

 

any idea how to fix or replace the purge actuator? it's in the rear of the car by the fuel tank right? at least the haynes manual said the evap system is there. i wonder how much that will cost me. also, is around 500mi around the correct time period for the sensors to come on? the manual told me 15-20 minutes is the time it take the computer to adapt to new settings. the stock ypipe has only been on for less than 100mi.