Cil Po420

Hi, I've got a 420 code on my 2000 Elantra. Assuming its the downstream O2 Sensor, does anyone have instructions on replacing this sensor? Is this something that has to be done by a repair garage?

Thanks!

Pete

You might want to get that code checked, I just replaced a downstream O2 sensor on my son's '99 Elantra and it read PO136. Check out the thread for this at http://www.automotiveforums.com/vbulletin/showthread.php?t=659364