P0446

[BSeward]

Well, about a year ago I had the P0446 code, and replaced the purge valve. It's a direct replacement with a common GM part, so it only cost about $20.00. I drove the car about 100 miles and it passed New York emissions testing. They allow a pass if there is no CEL lit, and a maximum of ONE code sensor reading "not ready". Which is what it was doing at the time, so the car passed last year.

I got the same code a while ago, and drove a few months with the CEL on, meanwhile looking around for a way to fool the NYState computers into passing the car with no money spent on repairs. They hook the car up to a computer/modem right at the inspection point, and data goes to DMV, which passes or fails the emissions test. No tailpipe test or anything the mechanic can do on site... Either pass or fail, and they barcode the inspection sticker so no cheating, either!

I determined that the EVAP system will not test if the fuel tank is filled over 85% full. So, figuring I had a month to mess with the problem, I cleared the codes, and proceeded to fill the tank with gas, not intending to let the level drop much before refueling.

I had the car go through 2 cold starts, and filled the tank 38 miles into the drive cycle...(only took 1.1 US Gallons!). At 47 miles I stopped in at my favorite inspection site (He sells me all my tires, and doesn't look too hard at the rest of the car - even though I keep the Woo in perfect shape). When I got there, he put a code reader on the car, and declared - "only one not ready flag" - bring it in! The DMV computer took a look at the car and immediately passed it. I refuled 125 miles later - 3.5 US Gallons!! and as of now - over 200 miles, the light is still off. However I expect it to come on again as soon as I do a couple drive cycles with lower fuel level.

This information may help someone who has an EVAP code on get through state inspection. Be sure to keep the tank almost full - even if you have to stop to refuel every 30 miles or so. My car completed the required drive cycles in less than 50 miles,
I filled up after clearing codes, next morining drove about 25 miles to work, and 8 hours later did another cold start to head to the inspection station - with a stop for gas. Maybe you could just reset the light, fill the tank and drive 75 or 80 miles, and it would still work. That experiment is for next years inspection....