California state law allows ONLY a certified smog check repair station OR a
vehicle's owner (him or herself) to conduct smog check repairs. General
mechanics are prohibited from performing any emissions related repairs, and
the state will not protect you if a general mechanic performs smog repairs
on your request and things go wrong.
There is no time limit on performing repairs or getting a smog retest. So
long as your car's registration tags haven't expired and you are not driving
illegally you'll be ok. As far as the smog retest... we do have to point out
that if the smog station you visited is giving you a FREE retest then you
might want to check with them about how long you have before you need to go
back to take the free smog check retest offer. The state of California
doesn't have limit on when to take a retest, but the station's free re-test
offer might.
