cat converter on 2004 Ford Escape

$900 to replace supposed plugged glowing red barley running cat.Ran good for two days.Back to same with loud air sound.Shop has had car for a week and can't figure it out.Thanks

Asked by for the 2004 Ford Escape
The cat was glowing red because the air fuel mixture was likely incorrect. If that problem was not addressed then putting on a new cat will not fix the problem, and the new cat will be damaged as well. I suggest you talk to the owner/manager of the shop and insist that they either get this addressed or you need to take it elsewhere and wish to have a refund if the other shop finds their work to be incorrect. Hold them accountable for their work!
Here's some related info: http://repairpal.com/blog/catalytic-converters-dont-usually-die-theyre-killed
2 more answers
As Bret very well said. The red hot. glowing catalytic converter was only a symptom, not the cause - which they should have repaired. This way they should replace a converter after every ignition cycle because the problem is still there.
I bet there is a fuel trim code also in the ECM.
Needs more diagnostics, check compression in all the cylinders, ignition and fuel systems too. It could be caused by several different faults, like a stuck open injector, incorrect, missing ignition, etc....
The car is using to much fuel and is burning it in the cat . It may have a bad fuel regulator .