How many miles do you get before you have trouble passing emissions?

[Jetronic]

I think everyone's idea of what constitutes an emissions test is different. Using the google machine, it appears 34 States require vehicle emissions testing.

Of the 34, I have no idea if any still do a tailpipe emissions test. I live in a PZEV State and we don't do them. Never did as far as I know.

It would be interesting to know how long a OBDII compliant vehicle could pass a tailpipe emissions test, given it's running as designed, with no MIL on, no codes, etc.

I can tell you what is needed in Belgium: For a gas enfine there's a sniffer placed up the tailpipe and it measures O2, Co, CO2, HC and displays lambda. CO has a max limit (0.5% i would think) and Lambda has to be between 0.97 an 1.03. Some cars get tested at idle others at 2500 rpm, depends on the year of manufacture.

If the car smokes excessively they can fail it for that even if you pass the sniffer test.

 

[SevenBizzos]

My "check engine" light is normally on. If I disconnect the battery it goes off for about 100 miles. They won't test the car with that light on. So the last two times I had testing, I disconnected the battery before testing and passed it.
In case you are wondering, I'm not putting money into a "check engine" light error on a > 200k mile car when my MPG has actually gone up a little since the light came on (and yes, I keep track of that too).

 

[kschachn]

My "check engine" light is normally on. If I disconnect the battery it goes off for about 100 miles. They won't test the car with that light on. So the last two times I had testing, I disconnected the battery before testing and passed it.
In case you are wondering, I'm not putting money into a "check engine" light error on a > 200k mile car when my MPG has actually gone up a little since the light came on (and yes, I keep track of that too).

That won’t work here in Southeastern Wisconsin. The presence of just the light isn’t the determining factor. All of the appropriate flags in the computer have to be ready.

 

[Gus_Mahn]

Two trucks ago I had a '97 4.6 F150. The check engine light came on twice in 340,000 miles ( plugged EGR passage, O2 sensor heater). It burned a quart of oil every 1000ish miles. I added over 150 qts of oil, and it never set converter efficiency O2 sensor performance codes. My wife had a 3.9 Lincoln LS with 200,000 miles. That CE light came on probably 15 times. In the rare instance it went off, I'd send her right to the OBD port test center. It just depends on the make and model. Some engines are more misfire prone than others and misfires seem to be the quickest way to destroy the converter/s.

 

[nickaluch]

My 2007 G6 beater at 105k has the check engine light on most of the time. A month before inspection I do two tanks of 93 octane gas. The check engine light isn't lite up passes inspection then back to 87 octane