DRIVE CYCLE

[farfrom]

I WENT TO HAVE MY EMISSIONS TEST TODAY. THEY WERE UNABLE TO PERFORM/COMPLETE THE TEST DUE TO THE FACT THAT MY OBD WAS "NOT READY". I DIDN'T FAIL, MORE LIKE AN INCOMPLETE. APPARENTLY THIS WAS BECAUSE I HAD THE BATTERY DISCONNECTED AND HAD NOT DRIVEN/STARTED THE ENGINE FOR SOME PERIOD WHILE DOING SOME RECENT UPKEEP/REPAIRS (NONE OF WHICH INVOLVED THE EMMISSION SYSTEM).

THIS LED TO THE OBD RESETTING ALL OF ITS STORED LEARNED MEMORY OF THE EMMISSIONS SYSTEM. SO WHEN IT CAME TIME TO COMMUNICATE THE STATE OF MY SYSTEM TO THE MVD, IT WAS "NOT READY".

I WAS TOLD THAT THE OBD NEEDED TIME TO RELEARN THE SYSTEM, AND,THAT A PERIOD OF TIME DRIVING, OR A DRIVE CYCLE, WAS NEEDED TO DO SO.

"CALL THE DEALERSHIP."

SO I DID.
ALL SIX OF THEM.
AND I GOT SIX DIFFERENT ANSWERS.
EVERYTHING RANGING FROM "30-40 MIN'S OF FREEWAY DRIVING SHOULD DO THE TRICK", TO NEEDING TO DRIVE "50 MILES OF REGULAR STOP-AND-GO AND 75 MILES OF FREEWAY." I WAS EVEN TOLD THAT I NEEDED TO "TURN THE ENGINE OFF THREE (3) TIMES DURING A 20 MILE STRETCH OF FREEWAYING (60MPH+)." ONE DEALERSHIP SAID THAT BECAUSE IT WAS A "LENGTHY PROCESS", THAT I COULD ALWAYS COME IN, AND THAT FOR $250, A TECH COULD RUN THROUGH THE DRIVE CYCLE IN A FEW HOURS TIME FOR ME!
SO MUCH FOR THAT.

I AM STILL UNSURE EXACTLY WHAT MY DRIVE CYCLE IS. ALL I KNOW IS THAT AFTER THE "NOT READY" I RAN SOME ERRANDS STOP-AND-GO, THEN TOOK THE FREEWAY HOME, TOOK THE TEST AGAIN, AND PASSED.

JUST WANTED TO PUT THAT OUT THERE.\

[Towncivilian]

Page EC-39 of the factory service manual describes the drive cycle in a probably excessively detailed manner.

From what I've experienced, sustained high-speed driving is part of the drive cycle for emissions readiness. In two cases now, I have had rear O2 sensor heater codes thrown after driving on the highway for 10-15 minutes after not having been on it for long periods in months.

[00pathyse]

When i had mine done in the fall, the guy told me to mixed driving 5 min of highway (or more), and 5 mins (or more) of city. I did this before my test and there were no issues.

[Slumpert]

My 1997 pathfinder takes a average of 170 miles to fully check the evap system.. Seriously that much driving and when I was trying to fix all my issues it was repair something and then wait to see if the light came back. The cpus on those models is craptastic in that regard.

So yes you can follow the driving modes or just drive it normally for a week and have it retested