i've googled and asked every tech i know about this, no one freakin knows. i just need to know exactly how long it takes to clear old codes from the history. the car does emissions checks and it takes a certain amount of time to complete the scan, leaving codes in the history even after you clear them. i got an inspection, failed because p2135 and p0496 were incomplete. throttle position sensor voltage correlation issue and evap purge solenoid. the car drives fine, nothing's up with it and i have minor bolt on mods. the car is hptuned. julian date is not within the "go f yourself date". the codes come up randomly. i am soooo pissed because i went a week with no cel and this morning it came back on. i seriously want to light this thing on fire. if I don't pass my registration gets dropped, then my insurance drops me, then the bank comes after me for having an un insured car that i still owe 7 grand on. help.