My 2004 xr6t mk2, with 128,000k shakes a bit at idle, but its not a miss and a power balance test comes up clean. Its got new spark plugs in it and its not an intake manifold. Only happens when warmed up and also my interior light flickers. Battery is getting a bit old, but still pulls 388CCA. Car cranks and starts fine, and the alternator has 14.4-14.9v output, also its running rich, but my oxy sensor is putting out an up n down graph, which is good... any ideas why the three faults are present? Are they all related? Also there are no related codes stored in the pcm.