P0496 code 2005 Chevy trailblazer
ok so my light came on...0496 was determined, replaced purge valve. turned light out...after a while came back on, replaced gas cap, same thing, vent valve, same thing, map sensor, same thing, fuel pressure sensor, same thing... smoke tested..passed... now I drive it for a while and the light turned out by it self but after like 4 cold start-ups It comes back on, so far it did that twice in the past 2-3 months now its back on...idk what to do thinking about replacing carbon canister and MAF sensor next.....I need help...
Why would you think MAF and MAP - Are there more codes? the test does not run all the time so several days may pass till next test. Check the purge valve for sealing, you can use a vac gauge on EVAP side of valve. My thoughts - Sometimes overfilling fuel tank after click off will degrade screen and allow carbon to obstruct purge seating... could remove valve and look for evidence. A scanner could be used to command system on and observe TPS (tank Sensor) change while vac cking at purge, confirm it will close and open vacuum.