I lean to the lazy for changing my oil
but i changed my oxygen sensor and problem solved
it got a little worse even with a few oil changes right on top of each other ( only waiting about 2 weeks between) to help clear out gunk. It started to 'cough' a bit while driving.
I borrowed the diagnostic from Auto zone and it read the problem in Bay 1 or batch1 or.. something like that.. I dont remember the exact where but it was only reading oxygen sensor and catalytic converter. I dont believe the converter is the problem. And changing the sensor is much easier and cheaper. Even if it was not broken, hey, its 120,000 miles old. might as well.
and.. so far so fixed