so i still can't pass inspections....i took it to another place, and the min. he plugged it in,

o2 sensor fail

cat fail. (clearly... since the last cat i have is up front)

so i tried searching for O2 sensor fail, well, a few different versions all with O2 in it, and i couldn't find anything.....but i vaguely remember topics about it long ago....

anyway, why do i have an O2 failure? is it cuz of the exhaust, CAI and TB??? doesn't seem to make sense......

oh and that intermittent CEL flash that happens? Apparently, it's caused by the O2 failure....is this true or false? and what should i do?

 

Maybe the sensor just failed. Sensors fail all the time. It's an imperfect world.


Or maybe you've got a fouled sensor. Either way, best thing is to figure out which one failed (or fouled) and replace it. Then you'll have to drive for a few days and get re-inspected.

 

hmm, okay, for o2 sensor replacement/repair, is it better to just goto the dealer?

 

hell no.. they'll charge you an arm & a leg.. some poor guy in my office has an audi.. they charged him $2k to change the sensors.. lol.

You might want to consider wideband sensors for future mods. I imagine only the rear is a bit tricky to get around.. you probably have to remove the intake manifold to get back there or get under the car to get access. I hope all of this drama gets resolved.. but I wouldn't worry too much. My neighbor has a 2yr expired safety inspection tag on a 5 yr old car.. lol.