Hi guys, I need your help / advice...

My '99 GLi 1.6 Civic's "check engine" light has been coming on and it's been diagnosed as a faulty o2 sensor. Problem is Honda wants $571 to replace it with new genuine o2 sensor from Japan. That's just too much.

Is there a cheaper aftermarket alternative available, and if so where can I source it from? How easy is it to swap out myself?

Really appreciate any help.

Thanks.