California Emissions testing

Is it safe to assume (yeah, I know, "assume" makes an a$$ out of "u" and "me") that a VCDS scan with no error codes will pass emissions testing? Anything in particular to look for?

Look at the readiness bits in both VCDS and in generic OBD-II mode. As long as the bits are flagged as tested/pass, it "should" pass emissions.


Some states will check to see if the car is modified and will clear codes. if a bit flips to pass after clearing, it will fail.

Santos said:

Look at the readiness bits in both VCDS and in generic OBD-II mode. As long as the bits are flagged as tested/pass, it "should" pass emissions.

Click to expand...

AND there are no fault codes.

Santos said:

Some states will check to see if the car is modified and will clear codes. if a bit flips to pass after clearing, it will fail.

Click to expand...

Not "a bit" but certain bits. Bits that correspond to systems that aren't monitored are allowed to read PASS immediately after fault codes are cleared.

-Uwe-