Golden gear got my 1989 Nissan Sentra smogged and road legal. There was an annoying issue with the fuel cap/gas tank venting but they were very patient and figured it out. Either I got very, very lucky, or Alex knew exactly what he was doing, perhaps a little of both, but adjustments were made, and the car made it through smog affordably and drama free. I noticed my old Sentra ran and idled a bit smoother afterwards. Expectations exceeded. Keep up the good work!