Check engine light question

[bgibbs11]

General, very simple question I can't seem to find a direct answer for - My check engine light is on. I know the code and what to do to fix it. Once I fix it (replace O2 sensor), should I go ahead and turn off the CEL with my scanner or will it reset itself?

 

[BOSMECH]

Reset it with your scanner.
You probably also have the VSC off VSC Trac lights on also, why Toyota did this I don't know but if you do a zero point calibration they will be gone also.
I just did my O2 about 2 weeks ago also and did the full reset.

 

[BlackWorksInc]

Reset it with your scanner.
You probably also have the VSC off VSC Trac lights on also, why Toyota did this I don't know but if you do a zero point calibration they will be gone also.
I just did my O2 about 2 weeks ago also and did the full reset.

I believe Toyota's Logic is that since most if not all modern VSC/TRAC systems function by utilizing both the ABS system and the Engine control system (they reduce throttle, limit power, ect), then any OBDII DTC is going to more than likely be related to the drivability of the vehicle and thus affect the engine management system.

What I mean by this is that when an OBDII DTC is set (by law any DTC that can potentially affect emissions has to set the MIL, everything is up to Manufacturer discretion) some codes will default the ECM. For example if the vehicle has a DTC where it believes the Mass Air Flow or Throttle Body Position Sensor is dead it will default to a stored table of variables; but the VSC & TRAC system cannot properly function because it doesn't know where the Throttle Blade is and thus these systems are essentially shut-off. Toyota tends to be conservative so it doesn't surprise me they just made it so any OBDII DTC disables the VSC/TRAC systems; though I hear Nissan is even weirder in that TPMS lights can actually trigger a limp home mode in some vehicles!? (I have yet to confirm this one way or the other, just what a Nissan Tech told me.)

As for the original topic, It won't hurt to reset it with your scantool. It can take for ever for the DTC to clear itself as it requires specific drive cycles, monitors, and a certain number of good results to self-clear.

 

[unclebeansie]

I've got an '07 v6 and need to replace one of mine. DTC P0051 (Bank 2, Sensor 1) which I understand is the driver side one (for the v6) closest to the manifold.

Question for you guys that have replaced these. Is 22mm the correct socket size and any tips for getting at it (it's a pretty tight space)?