99 olds silhouette check engine light

When a catalyst damaging problem occurs the check engine annunciator will flash and the vehicles computer (pcm) will shut down a cylinder. This flashing light and rough idle is a warning. Usually prolonged engine operation with flashing annunciator will ruin the catalytic converter. ($400.00++ to replace) Important that problem is fixed before operation of engine is continued. Check the ignition leads in the back (right side) for chaffe damage or burns from exhaust collector. Could also be a mechanical problem. Do a compression check. Start there. How many miles on vehicle.

the cat converter is overheating because the engine is misfiring, get it to a repair shop ASAP, I would tow it, but converter damage has already been done.