how do you know if an O2 sensor is bad?

As of recently, i had my flexpipe replaced and since then it has been running like crap. It felt like it was running better with the cracked flexpipe. Is there anyway to look at it visibly if it is damaged or is it something you have to get it checked somewhere.

any info would be great.

thanks again guys

 

I think if it has a failure, it' ll throw a CEL,
did you try to reset ECU to see if it runs better ?



Modified by Siegfried at 6:45 PM 6/3/2004