So I been away for 2 months in Vancouver while my 04 TL been sitting in the garage which hasn't been started. Started the car when I got home yesterday for the first time. I replace the battery a year ago.

1. Car would not start and lights won't turn on
2. Charged battery with battery charger
3. Turn on car and crank over just fine. Left the car on for 30 mins.
4. Today tried to start the car and wouldn't start. The dash board lights would fade
away.

 

sounds like your battery will no longer hold a charge.

basically, if you are able to start your car, run a volt meter from both poles and you measure 14 or so volts your alternator is good, if you have 12v, your alternator isn't running.

Also, you can crank the car, rev it at 2000 rpm, and have someone disconnect the battery. if the car is still able to run, your alternator should be fine.

 

So the car is running just fine. Today took the car in for emissions and the car failed. Took the car to the manager of the emission place and told me since the car has not been driving for a while and the battery been replaced. I should drive the car on the highway and city streets to reset it.

 

that 'could' be true, the ECU learns and adjusts accordingly. I know on my cousin's race honda, everytime he does work on it and disconnects the battery the idle is WAY off and the max output isn't exactly all there.
solution is to just drive it for a bit and try again.

 

you need to do the idle relearn procedure, hold down the gas pedal for 30 seconds in the 2nd key position (lights on, but motor off). Then turn on the car and let it idle for about 15 minutes with radio, lights, a/c and everything else off.