Failed smog test...

in cali, you generally have to get the emission checked when you register the car for a new owner, the first time the car is registered in cali (like you just moved here), or every two to four years of owning the vehicle. you cannot get updated tags until the emission test is passed, which is my current situation. my tags are already two months overdue and now im scared of getting pulled over and car being impounded for expired tags, even though i paid the registration...
 
i kno bank 2 is the drive side, and sensor 2 would be the rear, correct? hence why i replaced the driver side rear O2. but im still getting the error code. any ideas? thanks for the help guys
 
i kno bank 2 is the drive side, and sensor 2 would be the rear, correct? hence why i replaced the driver side rear O2. but im still getting the error code. any ideas? thanks for the help guys

either it was the aftermarket sensor, or there is a wiring issue.

also for smog, all aftermarket components on the engine must have a CARB EO number specifically for your application. cats on 4.6L mustangs must be stock and unmodified to pass legally, the ones that are advertised as "approved" are not legal in CA according to the Air Resources Board.
 
so if it is the sensor i should take it back? it has a lifetime time warrenty.

my cats are factory, the guy just removed the rear two for some reason. the car still passes the emission test with flying colors. i only failed cuz this damn sensor problem. i guess if you have any check engine light or no memory you fail...
 
well you have to follow the diag sequence to disprove a possible wiring harness issue. also you should really go OEM on sensors, build quality is a lot higher.

if the rear cats are removed, then the sensor could actually be doing its job..
 
ok, i'll swap out the sensors to see if the problem follows it. what do you mean the sensor could be doing its job? why only one and not both the rear sensors? and if it was doing its job, why would it say "O2 circuit" and not something like "bank 2:too rich or lean", something along those lines? thanks for the help
 
ok i understand where you are comming from, but the guy who tested the car said i passed the emission testing part, and my car was within the accepted range. if the primary cats werent working up to par would i still pass the emission test for the machine?
 
im not sure what a TSI is, but the guy puts it on a dyno and sticks a sensor in the driver exhaust pipe. so you think after i move the sensors around and diag the problem, i may need to replace the missing cats?
 
im not sure what a TSI is, but the guy puts it on a dyno and sticks a sensor in the driver exhaust pipe. so you think after i move the sensors around and diag the problem, i may need to replace the missing cats?

tsi is the test they do in non enhanced areas, the car is not put on a dyno and run at 2500rpm and idle. what numbers are you getting? i would continue to go after the sensor issue, not ruling out a PCM problem or a wiring problem.