Ok, this one is weird...when the car has been sitting a while (12 hrs+) in the cold, it starts but does not stay running. It will fire up, idle for maybe a second, and die. After several minutes of trying this it will eventually stay running and all is normal from there. Doesn't seem to matter how many times I try - today we tried starting it a couple times, walked away for 10 minutes, came back and poof, it fired right up. Doesn't appear to be a fuel issue - the pump is priming fine and giving it a bit of gas while starting it up won't keep it running. I'm wondering if there is just a weak connection somewhere? Anyone ever have a remotely similar issue here?

AND

Bonus issue - emissions are due and the CEL is on. It has been on for the past several months since we had a crank sensor fail and drove the car 2 miles on either 2 or 3 firing cylinders. I'm assuming whatever wasn't firing was dumping the gas right into the exhaust, as the light indicates a bad CAT or O2 sensor. How hard is it to replace the sensors on these cars? I'm thinking one of them is more likely to be fouled up than the cat itself, but then again there are 130k miles on the car. Maybe it was the final straw for the cat. Any ideas or advice are much welcome.

Thanks in advance,
Tom

My 97 Sunfire GT did the same thing, it started and ran on 3 cylinders in severe cold. If I shut it off and started it again in 5 mins it ran fine. I read all over about the lovely 2.4 ignition coils being oh so picky about working under certain temps. I wrapped them in a light layer of thermal wrap and it hasn't done it since.

"Is that your exhaust or is that the sound of someone deflating a cat?"