I have a frontier i bought about a month ago.
the service lights on and my friend told me its an evap leak (scanner told us...)
Ive heard of many ppl replacing hundreds of dollars on canisters and sylinoids of stuff andit doesnt make it go away...
Stick to oem. When I worked at a shop, we would run into the same prob. We tried aftermarket gas caps and they would throw a ses for evap leak. However when we switched to oem the problem would be fixed. Nissan and gm were very picky about gas caps.