99 Alero error code and catalytic converter

My daughter had some work done recently at a local chain shop to her car and it was not a good experience. Her car was running very bad and she took it in. They replaced the coil tower and the catalytic converter. I saw the converter glowing orange before they replaced it. In a week it started have an intermittent miss which the shop could not diagnose. They referred us to another shop who fixed it by replacing the coil tower with a used one and we got the first shop to replace the other one which they had put on which was defective. NOW the service engine light came on. Second shop said the code was "catalyst defeciency" and that the first shop installed a universal fit converter which on the Alero you can't do. What's correct?

Welcome to AF!!

You can use a universal convertor on an Alero if it is of the proper type. I would check the O2 sensor behind the cat as it may have been damaged and is not reading properly thus setting the light. It is not hard to change and will cost about $65. You may even be able to pick up one from a wrecking yard to try and save some money.

If that doesn't correct the problem you may be forced to change the cat again. I would go back to the shop and have them reimburse you for their error if you have to change it again. I just love chain repair shops don't you?