My LC has always fired right up. But starting last week, it became very hard to start - cranks a long time, then barely runs until it warms up, then runs pretty much normal. Except that the check engine light comes on and off occasionally while I'm driving without noticeable loss of power. Infrequently, it will hesitate/die from stop at warm idle. Afterwards, I changed fuel filter, distributor cap & rotor, liked the look of the plugs. No change. Diagnostic codes are 22 & 28. The water temperature sensor wire looks fine and the O2 sensors were replaced earlier this year (old were factory, so no big surprise). Ideas / next action? fuel pressure at the cold start injector?