I got the P0455 code (large EVAP leak detected) this morning after I drove to work. I was sitting in the parking spot for about 2 minutes, still in "D" when it came on. I had the same code about a month ago along with some other codes that were related to my plugs. I replaced those and the engine has been running smooth since. I cleared the code again today, but would like to know how I can find out what could cause it. I have seen posts that call for a smoke test? Is that something that is DIY? The car does not seem to be running poorly at all, could I leave it and see if it comes back again in a month or so? If it only happens once a month, I would hardly call that a LARGE leak...

The hose that sucks a vacuum in the cruise control thingie that then pulls the throttle cable had cracks and came of on one side last week. Still need to replace that. Could that be the cause? It did come of previously and I cut it a bit at the end to get rid of the cracks as a temporary measure. Now it obviously just needs to be replaced entirely.

Cheers!

 

A 455 is a large leak, which won't effect how the engine performs, but will allow gas vapor to escape.
If you don't find or know how to track down this issue, a mechanic may be in order.

 

I don't mind using a mechanic, but I would like to give it a try myself before I go through that expense. Where would I start?