Check Engine and ETS lights...........

Both Check Engine and ETS lights came on upon startup one morning. They've been on ever since (two weeks). I had autozone read the codes for me: 342 and 440. The book at autozone listed possible causes:

342: camshaft position sensor bad, connections and wiring to sensor bad, or timing belt/chain out of time.

440: Fuel cap, evap canister or hose is cracked or not connected, purge or vent solenoid defective, vacuum leak at engine.

Now, the engine runs just fine so I can rule out timing belt. Already installed a new gas cap, that didn't fix it. So i'm down to: camshaft position sensor and connections, evap canister, purge vent solenoid defective, or vacuum leak.

Why would I get both ETS and Checkengine lights on? What is common to both? Has anyone had this scenerio before? Not sure how to check the vacuum leak, evap canister, purge vent solenoid etc........so I thought I would ask before digging deeper into my Chilton's manual.

Inputs?????????? (please don't tell me to reset the codes and/or disconnect battery)

I have had the same problem for about two years. They'll come on for a few weeks or so and then they'll turn off. Then they'll be off for a month or two.

the ETS off light will come on for the most darnest things, trust me. The evap one is most likely from the changing weather conditions. I'm getting alot of those codes at work right now. Just make sure your atleast getting 3 clicks when you putting the cap back on. As for the CEL... Start lookin for a bad ground somewhere. If your car is running fine its most likely that.