Seems I'm experiencing several issues. O2 sensor replaced, right front engine mount..upper engine mount...lower engine transmission mount all replaced. Now I'm getting a vibration and rumble noise when at a stop, engine running in either drive or reverse. All smooths out when moving or when in neutral or park. The upper and lower mounts are the polyurethane variety and reportedly are stiffer than the OE mounts. It was suggested that I loosen the upper and lower mounts. Start the engine, put in drive, then reverse with the brake on of course. Then retighten the mounts. I haven't done this yet but thought I'd put this post out for comment.