ticking sounds at idle

[mpaulson]

My truck has about 69,000 km's on it and sometimes but not always, at an idle when you stand infront of the truck it has a ticking sound that sounds like it could be a valve or something. What gets me is that it isn't consistent. I would think that if it was a valve it would always be there. Has anyone else noticed this on their trucks? I have the edge juice chip, does this chip increase the uel line presures? Could this be a fuel injector that I'm hearing?