History:
Vehicle sat in garage drained of water and waste, and clean, stabilized gasoline (full tank) and w/o batteries from November 30 to April 27. Batteries added and it started without difficulty.
Out of gear and sitting, engine will track smoothly up to red-line and down again without any roughness. In gear and under load when the engine hits ~2,500 rpm it is like hitting a wall - the power drops to 0. Let the RPM drop, bring it back up slowly, it engages again. Same at any speed. By feathering the throttle, I can get it to any reasonable speed, but not hold it at that speed without continuing to feather.
And, the second time it was run (after sitting overnight), the Check Engine light came on and remains on.
No undue smells, no smell of unburnt gasoline. No rough idle, no rough running.
~97,000 miles on it. Always synthetic oil, always changed regularly (at least) once per year at the beginning of the driving season. Averages less than 5,000 miles per year, however.
My first guess is Oxygen Sensor. I do not have a OBD II tool, but if advised to get one. And any other helpful suggestions are welcome.
Thanks in advance.
Peter Wieck Melrose Park, PA