Red hot catalytic converter

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! If your 2000 Mercury Grand Marquis has a red-hot catalytic converter, that’s a sign it's either overheating or clogging up. This can happen if there’s unburned fuel reaching the converter, which might be due to a misfiring engine, a bad oxygen sensor, or a rich-running condition. Letting it sit still and idle for long periods could make it worse, as the exhaust gases aren’t flowing as freely as when driving. Running it like this can damage the converter, so I’d recommend getting it checked out ASAP before it causes more trouble. If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554!