Hmmm, I think some of you guys are misinformed, first if you take it to Autozone the scan tool they use is gonna be a generic scan tool which will only give you a sort of direction to go in or system that's failing. Autozone is great for free but I've always been scared of a parts house that do free diag's of Mil lights(check engine light) and have absolutely NO training in that field. A dealership uses the factory scan tool to pull codes and is much more specific on the code, and generally will provide what they call a "freeze frame" of engine conditions at the time the light was commanded to come on. This is a helpful feature along with others like a factory trained tech using the tool, Factory Techline which can be very helpful in giving common fixes for reoccuring complaints and problems within say the 99 model passport. Also in your case i know that it would be more specific in the evap system, for instance the code would be say a p0456 or a P0457 which would tell me that it's a leak on the fuel tank side or the canister side, which could reduce diag times and get the right part/fix the first time so you can get down the road again. I think Autozone would be a little more guessing it.

Also OBD2 codes do not just go away after a few trips, they are designed to stay on until cleared by a tech after diag and a repair is made. Sux but thank uncle sam and the lefty enviroheads who thought this would somehow save us all from the "Evil" smog. Did you know that one volcano produces more harmful polution than all the cars ever made in the last hundred years? hmmm maybe we should smog volcano's

I think carl sule sayes a dealership average customer who buys a car is worth like 30k to the dealership or something like that(someone help me here if you read the book,"customer's for life")

Honestly i think your calling a dealership a "stealership" is pretty lame, I mean nobody's forcing you to buy a car or service it from a dealer. I have invested half of a price of a decent house in cali for tools, tons and tons of hours of time training to be a better tech and I am always fixing cars for "free" as a thank you from me to my customer for bringing the business to me. I think it's unfair to label all of us that way, there are good techs out there like me who don't deserve that. ask my customers who have followed me over the years from the honda dealer to the acura dealer I'm at now.

I think that that other guy had a better idea then the autozone thing, buy a manual, preferable a helms and jump the "scs" connector with a paper clip to retrieve your own codes, super cheap and works most of the time really good.

Sorry for the ranting, just thought I'd maybe share a little and hopefully someone will gain something from this.