Just my 2 , I have had mixed results on this , threw both 0440 & 0420 when I first installed , went ahead & replaced both rear sensors & haven't thrown one since (kiss o death). However very pleased with results SO FAR ! Have a/f sensor standing by in case !
This depends on one thing. Which engine do you have? I believe it will on a V6, but my V8 did not have an O2 sensor after the rear cat, so mine happened to disappear one day at my dads shop, and a y-pipe was there instead. I wouldn't say you get much for performance by just that, but the sound is great with my Magnaflow on it. Every little bit counts and starts to add up though. Unfortunately with the V8, there isn't really any performance mods we can do other and modifying the intake. At least that I have found I should say. So.....Short story long? Look and see if you have an O2 BEHIND the rear cat. If there isn't one, go for it. No lights will come on.