This article Check OBD II Monitor Readiness Without A Scan Tool | JUST SMOGS® + REPAIR describes how the driver can determine whether the vehicle's computer has completed the required emission "tests" and is reporting READY for emissions testing for various manufacturers, but not Toyota. Is there something similar for the Prius? I have an OBD-II scanner which reads fault codes, but I don't think it reads readiness. I understand that usually driving 50 to 100 miles will mark all tests as completed, but don't want to risk being rejected from testing after clearing a code and then having to go back.
I don't know of such a shortcut. Techstream will show you the monitor readiness, of course. Just driving normally for a good lazy while ought to do the trick, unless, say, you have recently cleared a code as an alternative to finding and fixing the problem reported by the code, and you're trying to squeak in an inspection between monitor readiness and the code coming back, which I won't assume.
ScanGuageII will tell you if the car is good to go for inspection. Instructions on p 35 of User Manual v. 6.2: You go to the home screen and press 'Scan' (upper left button), and you'll get 'No Codes Found', and 'Ready' or x Stored Codes and a button to view those codes.
Guilty! Apparently every few months I apparently purge some gas tank fumes to the ether. Luckily, our president says there's no global warming or I might be concerned. I have codes P0441 and P0455. Got a new OEM gas cap, but no love there. Very random and sometimes months in between codes. Thanks to all who replied. Apparently, I'd have to drop some not insignificant bucks to get a better OBD II scanner or app that would also read readiness. Kinda trying to save those bucks for the eventual repair.
