Recently my car had a SES(service engine soon) light, since I was trying to replace an O2 sensor and the O2 sensor bung stripped. Had to have a shop rethread the bung and connect the new O2 sensor. They reset the ECU and cleared the SES light. i mentioned taking it to get smogged and the tech said to drive it around for a few days before going to smog.

Apparently after ECU reset for OBD2 cars there is a period where OBD2 monitors have to come "online" before trying to smog or it's an automatic fail, at least for California standards. I tried to do some searching regarding this and saw various situations regarding these OBD2 monitors. Some mention having to do an entire procedure listed in the FSM which involves things like turning ignition on/off/on, driving at 50mph then slowing to 30 repeat etc...Others drive it around for a few days and pass smog. Some never get some of the OBD2 monitors online unless the dealership does the FSM procedure for them. These instances I mention are from different makes of cars with ODB2, since i can't seem to find anything on the VQ35.

I see a Basic Service Procedure in the Engine Control System portion of the service manual that seems like a process that needs to be done after resetting the ECU. It includes procedures like:

PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING

PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

Idle Air Volume Learning

driving at 50mph then lifting the throttle to 30mph, repeat. 3 or 4 times.

etc...

Anyone know if this procedure is necessary to get the OBD2 prepped for smog or do I just drive it around for a couple days?

Thanks for any input.

 

You don't need to do any of that. Just drive around for 50-100 miles. Thats how long it takes for the sensors to read what they need to read. Drive it for 2 days or a few more if you can, but you'll be fine. You don't need to do any special procedures.

 

they arecalled system readiness tests, and they are tests that the car does on its ownwhile driving while the parameters are met. If you look in the service manual it will give you the SRT drive cycles to make them all complete, it must be strictly followed.

most 300 dollar (and up) scan tools have SRT support function on them.

and yes like the guy above me said drive the car for a few days and the tests should complete the drive cycle is only really for us tech's who don't have a couple days to get teh car to go through the SRT's to confirm the vehicle has been fixed. IE: Evap code, if that srt sets then the car is fixed. and so on and so forth.