I'm stumped too.
You may have to provide more clues in order to stir up some imaginitive thoughts on this forum.
- odometer reading?
- service history?
- ownership history?
- did it start this suddenly or intermittently at first?
- is the car kept inside or outside overnight
- any recent repairs done?
- any aftermarket electronic devices such as alarm/remote start?
- is the warmup time still the same as it always was?
My first thought was something to do with the secondary air pump.
Because that is in operation only during warmup, and any noise from it would be heard on the passenger side of the engine bay.
Could be a vacuum problem while the pump is in operation.
Anything ever happened that could have damaged the cats.?
However, the clicking noises during the misfires sound like a relay in the area of the fuses behind the glove box.
Any thoughts about the fuel pump?
Could have developed a fault that is only an issue when vehicle is cold?
Even though there is no SES light, you may have to pay up to get the dealer's computer to reveal what codes are there from the misfiring.
UPDATE: I see you do get an SES - but this normally stays on, so you can get it read easily.
Last edited by Supercourse; 03-13-2010 at 02:28 PM.
Reason: Added info.