I took my car to the shop in early moring without warming up the car , or driving it for a few mile.
and i failed the OBD monitor test:
catalyst, evaporative system, oxygen sensor, and EGR system were all in not ready status.
Technician there told me to drive 50-150 miles and take the car back to be retested. He said this should fix the problem.
What can I do to pass and how long should I drive the vehicle?
I've heard a lot of stop and go driving can cause some carbon build up on an exhaust system. What a long drive does is heat it up enough to burn off the carbon. Pick a place to go some weekend that will take several hours to drive there (Virginia Beach to Richmond, for example) on any highway that will give you several hours of non stop driving. Try the inspection again a day or so after your trip.
Taking a longer drive does help - and use a tank of high test gas before/during the test. I've heard that helps burn it out too. I used to live in MD, and I was always worried my van wouldnt pass - but a longer drive on the highway - up and down 95 always did the trick. Good luck!
My last car did this ALL the time. Take a long drive and drive at 25 MPH for 15 minutes, 35 MPH for 15 minutes, etc. until you get to 55 MPH. That helped me.
I'm not sure how long you need to drive to fix it, I'd just go the distance the mechanic suggested.
To avoid this happening again, don't drive short distances as a habit. It wasn't just the one short drive to get it inspected that caused this. The "build-up" happens over a period of multiple short drives. And not only will you fail inspection but it is hurting your car. You don't need to drive super-far every time, just try to keep it above 5 miles or so... Good Luck!
