Cadillac CTS First Generation Forum - 2003 - 2007 Discussion, O2 sensors in Cadillac CTS Coupe, Sport Sedan and Sport Wagon Forums; I recently went and got an emissions test on my 2004 CTS 3.6L they told me all 4 o2 sensors ...
I recently went and got an emissions test on my 2004 CTS 3.6L they told me all 4 o2 sensors were bad and they needed to replace them all. They gave me a bill of 3500 bucks. The check engine light was never on. How do I tell if they are bad ( the sensors themselves)
$3500 to change out some O2 sensors...hell for that price i could fly to you from germany, buy the parts, replace them (although the top two can suck to change), fly home and still have made a profit...did you go to an independent mechanic or a stealership? if you are somewhat mechanically inclined, i suggest watching a How-To video on youtube and doing it yourself. if you dont have the time or ability, then find somewhere else to go to have it done if all four sensors are actually bad (which i would bet that $3500 that all four are not bad, maybe one or even two but not all four)
RockAuto lists 06 CTS O2 sensors for $35 to $165. I know labor is involved, but ~$3000?? All four went bad at the same time? And no codes are displayed? Definitely get another opinion, and if need be, report this guy to the state. This is why many states have ditched their vehicle inspection shakedowns, and if you're lucky (as we are in Oklahoma), they'll do away with the emissions testing as well.
I've actually done this. The o2 sensors after the cats are easy. the two ahead of the cats are easy to get to if you remove the catalytic converters. The difficult part there is removing the nuts holding because they're going to be rusted on. You don't need to remove the entire exhaust, just the cats. If you do choose to do the job yourself, be sure to replace the nuts with stainless steel, or at least use anti-seize compound on the threads,