I've got a 2004 Tacoma with the 2.4L w/ the 5-speed and I just can't seem to get rid of a rough idle when it's warm. It's not terrible but does feel like it's getting slowly worse - I've cleaned out the IAC which I think helped a little. (Could be my imagination+wishful thinking) I also changed out the motor mounts, spark plugs, and fuel filter to no effect. The truck has 60k miles on it and has never even given me a CEL once. No other signs/symptoms, and I don't see anything immediately hinky on my autel. Any thoughts? Can an ignition coil go bad without a dash light coming on?