Changed catyletic converter new one glows red what could be problem?

Glowing red catalytic converter means your car is injecting too much gas, more than the spark plugs can burn up efficiently in the cylinders, or you have a serious misfire, so multiple cylinders are sending unburnt fuel into the exhaust system, where it will ignite inside the catalytic converter due to high heat. find the cause of excessive amount of unburnt fuel getting into the exhaust system. don't run it like that too much or it will ruin your new cat. quickly if it is glowing red... incorrect timing of engine, severe engine misfire, possible causes.