Hi all.

Quick question for those who may know...

How long does it take for the monitors on the ECU to ready for smog? I recently had my Oxygen sensor changed out and my CEL went away. However, I checked the monitors on my ECU and it says all are ready except for the catalyst and Evaporative Emissions something something.

Second question is... do I need all the monitors to be ready in order to smog?

Thanks in advance.

Car is a 1997 Subaru Impreza L.

-Kevin

 

General Rule for anything OBD-II is 15-30 minutes for the Cat to completely "Light Off" and all the system checks to have gone through. Same thing any Smog Station will tell ya.

 

50 miles. That's what I usually do.

 

not about miles. constant speed of 60mph for about 15-20minutes

 

also make sure you drive it hard on the way there.
Cat will burn/heat up and lower #s
did that for my hi-flow catco on the civic with cams and it still passed...barely

 

Okay... I am confused... so... those monitors goes off after driving for a certain amount of time and not with miles driven. So... if I turn my car off, those monitors will reset?

 

no. IF!!! you clear your memory from a cel clear or disconnecting battery then it resets monitors. Once its set, it will stay set until your car throws another cel or battery is disconnected or memory is cleared

 

Your allowed two monitors to be incomplete.

 

I am sorry. I think I misworded the question. I didn't clear any codes or reset the ECU. My question would probably be better stated as... Do any monitors reset after I turn off the car?

As for the statement on incomplete monitors... I have two... evap and catalyst. That should be okay for a pass?

 

A hard code will not reset until it is cleared
a soft code like O2 bank1 error will clear it self once repaired.
My friends civic HX had a failing primary O2 and a cel, but once we replaced it with a new OEM replacement O2, he drove it for about 40 miles and it cleared it self.

 

*Under the new "STAR" rules, no. Reason being is both of those are main players in emissions.

Pull the battery, take a 15minute break, reconnect the battery and go for a drive at the speed and timespan Anthony and I mentioned and then see if your codes are fully clear.

"How come your EVAP and CAT are coding?" would be my reasoning.

 

Okay. I got a 100 mile drive ahead of me. I'll pull the battery and do a reset. Might as well.

 

Okay... an update. I've driven about 100 miles, give or take. All the monitors are ready except for my Evap and my Catalyst. I guess I'll keep on driving.

 

do you have a full tank of gas? Some monitors dont set when it has more then 3/4 a tank of gas.

 

Nah. I had a half tank when I reset. And am now down to 1/4 tank.