Who really understands codes and emission testing?

[sweetk30]

its NOT faulty if it has not yet run and passed or failed . . . .

 

[leverhead]

Weird thing is that now that I know what I'm looking for, I looked on the reader and the EGR test has run and passed. So it must be some intermittent thing. The O2 test has not run, and surfing around I see that some people have had real trouble getting the O2 test to run. Looking on the AZ emissions web site, they allow one test to be not run and you can still pass. So, if you have a reader and clear the codes, I guess you can have one faulty system and still get by as long as you go to the station before it runs and fails.

Your EGR valve may be on the way out. As far as the O2 and the state, it may be a matter of semantics regarding the one test exemption whether a test is regarded as 'not run' or 'run/failed'. May want to call the testing station to find out first before you waste time and money. I think I remember when resetting everything that the O2 was the longest to re-set. If you can get by with the egr and the rest of them, forget the O2 and get it tested then....who knows...the O2 may re-set before you get there. Bring your reader with you and check it before you pull in.

 

[Wes Harden]

Most 02 sensor require a 10 to 15 minute 50ish mph steady run run to set. Sometimes activating the brake switch will stop an in progress 02 test.
I forget what your car is, but all manufacturer have process to make the the monitors run. Should be published on internet somewhere.

 

[JoshHefnerX]

I drove my Camaro through the GM drive cycle a few times and several hundred miles. Most will pass pretty quickly, but occasionally they will take a bit longer. Google up the GM drive cycle. There's a specific set of driving circumstances that are 'supposed' to get them to pass pretty quickly.

edit: This one says vw/audi but it's identical to the one from gm I think.