Passat problems

Four days and a thousand miles after getting the Passat back from having its timing belt replaced, heads machined and all new valves the check engine "Emissions Workshop!" light comes on.... Of course it's Sunday on a holiday weekend and we're a thousand miles from home. Several sites on the net suggest things such as a problem with a vacuum line, not having the gas cap tight or a misfire. Maybe it needs plugs... the annoying thing is it's impossible to tell. From now until Tuesday morning when the shops open up we're clueless.

So somebody should come up with a tool that will plug in to the car and give mere mortals the readout. Bonus points to somebody who makes one that is a small LED or LCD display that can be mounted near the dash instrument cluster.