SMOG Question...... possibly simple...... hopefully

[PRE-H20]

Hey Fellas..... so I have a quick SMOG question..... my tags are due HAD my check engine light on... I've made some minor repairs, I used my wireless OBD2 and cleared the codes. It's been 2 days and no check engine light.

I'm curious how many miles do I need to drive PRIOR to taking it to get the smog done after clearing the codes via OBD2?

I kinda remember someone saying the car needed to be driven 50-70 miles and normal around town stops and starts.... but I cant remember.

I dont care of the light comes back on AFTER passing smog and I plan on driving freeway speeds for a few miles to get it nice and HOT before pulling into the smog station, BUT I'm curious how long I have to wait post clearing the codes....

Any SMOG Guru insights ?

[3rd_gear_Ted]

Your car will be hooked up online and the "system" will check if they think its OK.
The DMV referees @ Cal State Fullerton is who you should talk to about the nuances of your situation. They use the students to do the tests and they are very thorough.

[Deschodt]

That only came up for me when I UNPLUGGED the battery and the car was therefore not "ready" for smog test, not enough miles, and required a complex drive cycle that is hellish to reproduce (E46 M3, the worst). Simply clearing a fault never did that, but I suppose it's possible. Simply use your ODB tool to check the "READINESS" of the car. If the reader returns any codes like "not ready" or "n/c" then you need to drive some more. if all "OK", you are good to go.

[pete3799]

Can you access your readiness codes with your OBII?

[aigel]

You need to make sure the readiness monitors are set. Any halfway decent obd reader will show their status. And yes, it usually takes some driving to get them all to trigger. Some early OB2 cars can struggle to get there, that’s the only time you need to worry about a referee

[masraum]

Originally Posted by PRE-H20

Hey Fellas..... so I have a quick SMOG question..... my tags are due HAD my check engine light on... I've made some minor repairs, I used my wireless OBD2 and cleared the codes. It's been 2 days and no check engine light.

I'm curious how many miles do I need to drive PRIOR to taking it to get the smog done after clearing the codes via OBD2?

It depends because it's not a straight "X miles and you're good" sort of thing. I think it is a variety of starts, stops, miles, speeds, etc....

Does your reader show "ready"?

My reader will show "ready" when I hook it up. I'm pretty sure that "ready" may be the clue, but not positive.

[john70t]

AFAIK every manufacturer and/or vehicle has different conditions to be met first, and some may not make sense.
The dealership might know.

https://www.underhoodservice.com/forcing-vehicle-monitors-for-calibration%EF%BF%BC/
https://www.jdpower.com/cars/shopping-guides/how-to-perform-a-basic-drive-cycle

[Bob Kontak]

Originally Posted by aigel

You need to make sure the readiness monitors are set.

What is the year, make and model of the car?

Post the above so one of us can find you an OBD drive cycle that you can perform to increase your chances of clearing the monitors.

There is no number of miles for any car. Garages will tell you to take it out and drive around for a few days but what they wont tell you is how to drive it because they just want you gone for a while.

It's getting more wierd as some states allow the EVAP monitor to not be cleared yet they will pass you. Assume you don't live in one of those states. I do but Ohio will not admit to it.

It's witchcraft, I tell you.

Edit: What John70t says, too. One thing his generic drive cycle link does not have is drive at 60 for three - five minutes and let the car coast to 15-20 without touching the brakes. it's hard to do this on the expressway. Have 20% to 80% gas in the tank and let the car idle at start with no brakes no gear engagement. Defroster, lights, AC on to create electrical load. Several minutes.

[masraum]

Originally Posted by Bob Kontak

It's witchcraft, I tell you.

That's how I've always understood it to work. I've cleared codes, drive as usual for 3-4 days, and check for "Ready" and it's always there. No idea how I did it, but I did it.