A local repair shop told me today the reason my SES light is on is because both my upper and lower oxygen sensors need to be replaced. They want a total of $360.00 for the job (parts and labor). How hard is this to do? I use a mobile mechanic from time to time. I checked advanced Auto. I can buy both sensors myself for about 140 bucks I think. Are these things hard to install? Can I save myself a little money by having my mobile mechanic do it?
What do you recommend? TIA for any replies. Is this more of an environmental thing?