OBD emissions test

[Jengle]

Has anyone had an OBD only test for emissions? My county just required it on all diesels from 1997 up. They say there is no visible smoke check or anything else, other than an OBD test. What is that? What will show up there, that they are looking for?

 

[WoodChuck]

Maybe a programmer.

 

[SierraRam]

They are looking for any codes and a presence of aftermarket programmers and chips.

 

[Matt400]

They will plug into your OBDII port and look to make sure all the tests have run (because clearing a code will reset all tests back to 0), no fault codes are logged and the CEL is out.



Lets say you have a chip or some other item that causes a CEL so you stop a block away and clear the fault codes. The Tech will see that all the tests have not run in which case you fail.



The system continually runs tests all the time while you drive and when a test fails that is when a CEL can come on. If all tests have run, the CEL is out and there are no pending codes you should be good to go.



The shop running the test should be up front and tell you exactly what they are looking for so you know ahead of time what to expect so you can pass. If it seems secretive then I would find another shop.

 

[JJPage]

Has anyone had an OBD only test for emissions? My county just required it on all diesels from 1997 up. They say there is no visible smoke check or anything else, other than an OBD test. What is that? What will show up there, that they are looking for?

I was hoping for just a plug in test, to look for codes, because that is what they did to my daughter's Honda. No such luck, Spokane County requires a "snap" test for diesels.



Your lucky to be in VA. I failed the snap test the first go around, they allow 40% opacity, my truck was at (I THINK) 53%, which was the best out of about 10 tries:-laf.