Yesterday I replaced the o2 sensor on my '98Civic Dx. I did this after a test from Autozone said the sensor after the cat converter was faulty. This morning on my way to work the darn check engine light illuminated again. What could the problem be?[:@]

 

wel maybe you should trust the guy, maybe your cat is bad. And if you need to replace it, maybe you could get a nice name brand high-flow cat and get an extra hp or two

 

Magnaflow makes nice cats. Don't go for the "racing" cat tho b/c that's straight thru + I'm pretty sure u won't pass inspection.

 

The Autozone guy said it was the sensor that was bad, not the cat

 

have them look at the sensor under the hood

 

did you clean the mating point of the sensor with the pipe with a wirebrush? Corrosion there could compromise the ground connection.