Mil/check engine light smog test failed - 1999 Chevrolet Suburban

SOURCE: Jetta failing smog due to non communication with OBD - Suggestions?

the no data error can be contributed to a bad interface cable or the scaqn tool was configured wrong and therfore could not connect to the ecm. I would recommend having a scan done again by a certiefied volkswagon tech chances are the mechanics used the wrong adapter cable or reader card. your smog problem could be that your evap canister is clogged therfore gives a bad reading.unfortunately you have to have a scan done but try an independant small shop that delas exclusively with foreign cars such as porche andd mercedez. the will have the correct scan tool and will be much cheaper than a dealership. your cost should be no more than 50 dollars US ... please rate this. thanks

SOURCE: 2000 Saturn SL2 fails smog due to failure of OBD Self test

Some vehicles require very specific drive cycles (called "drive traces" if you perform them on a road simulator or dyno) to activate certain self-checks like the catalyst and EVAP monitors. As a general rule, doing some stop-and-go driving around town at speeds up to about 30 mph followed by five to seven minutes of steady 55 mph highway speed driving will usually set most or all of the monitors. Consequently, if you're checking an OBD II system and discover that one or more of the monitors have not run, it may be necessary to test drive the vehicle to set the remaining monitors.

You should talk to a good emission tec, if this is not throwing a code, it is hard to say if that one of the components could be bad. O2,pump,convert, HeO2, every part of the emission system.

With a 1000 miles, and doing what is says above just before the test, and ending driving at the test
should be plenty. If it is not, you will have to have each emission part checked, or when the computer
is plugged in it might show a code that did not trip dash light.

Ned C Cook

• 3433 Answers
• Posted on May 07, 2009

SOURCE: Prerunner wont pass smog due to engine service light

Not positive on this so consider only. The o2 sensor is what actually tells everything else what is going on with emmission and everything else adjusts to what info it relays. The o2 is also subjected to extreme temps and cooling cycles. So, instead of spending money on no answer diagnostism give replacement of o3 sensor so consideratio. If you choose to replace, wd40 and let exhaust cool down. Good Luck.

SOURCE: 2003 Toyota Camry Se V6 has a check engine light

They may have disconnected the c o sensor.Check that first.If they haven't disconnected it.Change it and have the coeds cleared.Good luck

SOURCE: My 2002 VW Jetta failed smog due to MIL/Check

Ok. The car performs a bunch of silent self tests when you are driving. One of these, and if I had to bet, would be the evaporative emission tests- basically the car checks to make sure any evaporating fuel is going where it should be, and not getting released into the air to pollute, blah blah... What this has done, in addition to remove a teeny tiny amount of pollution is to drive techs and car owners crazy.
The car wants a certain speed, distance, temperature, and moon phase to complete these tests. If you are only traveling 15 miles back and forth to work everyday then the car might not find the "ideal" condition to finish the tests. This weekend, go for a drive somewhere. Somewhere far, so you have to burn through a half tank of fuel, at the very least.