Hi all, the smog check on my 2006 MCS was failed due to the following error:


Your vehicle failed the Smog Check inspection due to the fact that the vehicle's on-board computer system has not completed the emission system's self-checks. IF you believe that this result is in error, you may want to schedule an appointment with the BAR Referee at ...


The body shop said I needed to go through a "OBD II drive cycle", which consisted of some very specific acceleration/stop patterns, among other things.




I tried my best in going through the cycle, but still no go. So my quesitons:

1. What exactly caused the error? The emission guy basically said the reader couldn't pick emission information from OBD port, and going through the cycle will "feed" the missing information.
2. What are my options in case it still complained about the missing stuff?

All my previous smog checks usually took about 20 minutes, this one really pullzed me... the car doesn't have any warning lights on.


regards,

 

Do you have your own obd reader? If not you should get one. Otherwise go to auto parts store and see if they can pull codes. Autozone or similar chain does this for free.

 

I do have one, but it didn't return any error/warning code..

 

Ok, it turned out to be the following code:
P0420 Catalyst System Efficiency Below Threshold Bank 1.

After some research it seemed a quite popular issue, and implying a new cat.
I wish that won't be the case, will swapping a new O2 sensor help? I replaced both of them around 100K miles, and my car currently around 110K.

Or would I better off having mechanics for a more comprehensive diagnose? A cat shouldn't give out that soon...

 

You could try the O2, but most of what I see leads to a bad cat unfortunately. Some good info HERE.

 

Just had this same issue today, must have caught the new guy at the dealer, as stated and worked like a charm

Drive 55mph keeping your rpm between 2500 and 3500, fuel tank has to be between 3/4 and 1/4 full.

This forced the computer to run the O2 diagnostic wich was reading incomplete when i tried to get it smog checked.

i was told to get behind a big rig because there max speed is 55. well i just angered everyone passing me ( including big rigs) for about ten miles both directions went back to same smog place and they said it was ready