Hey Folks,

I'm trying to chase down a problem with my v40 check-engine light and I noticed a couple other recent thread-posters here are also doing.

The code I am reading (Thanks Autozone...) is : P0455

This code relates to something with the gas-tank/gas fumes or evaporation mitigation system.

My first question boils down to this... I have been told that this could be as simple as the gas cap not getting cranked down and sealed properly, so this is the place to start. Being cheap, I have not as of yet baught an ODBCII reader that can clear codes. I was told that I could get around this (clear codes) by disconnecting the battery for a while. I tried this both at a half-hour interval and then overnight, but the code seems to remain. The check engine light remains on the instant I restart after reconnecting the battery. Is this possible, or does the code get thrown so fast at start-up that it looks like it was never purged? Is this battery trick perhaps just a myth, and the little brain can hold onto codes in flash-memory somehow?

OK... so my second question is... I think I may want to finally order a ODBCII reader from amazon... Can anybody tell me what I need to look for? I am not familiar with such terms as "can-bus" and "ELM327", and the number of product choices on amazon is a bit daunting. Are there some certain features/protocols/parameters I must look for for my 2000-v40 car?

Any tips or opionions on makers or versions of this tool, and whether to go with a handheld one, or the ones that can connect to a laptop or iPad via wireless?

Thanks as always!

- Wingy