I just got a used 97 pontiac sunfire with 125,000 miles. it runs good,im just doing a tune up to get better gas mileage. Im putting new spark plugs,spark plug wires,and a new air fillter. My question is should i replace both o2 sensors with my tune up? There's no check engine light on, and it runs pretty good, or Should i only replace them when they go bad/check engine light comes on?
Jan 28, 2010 at 1:32 AM