Code 21 when WOT

[Beefierspade]

As title says, but no codes when idle or cruising around. However as soon as I step on it to have some fun code 21 pops up. Turn car off and start up again and code 21 is gone.

Anybody have insight why this is? Circuit shorting out at certain voltage?

 

[DeMoN2318]

And you cleared the codes and it comes back?

Have you checked the O2 sensor wiring?

Checked the O2 sensor??

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=119

 

[Beefierspade]

And you cleared the codes and it comes back?

Have you checked the O2 sensor wiring?

It clears itself when the car is turned off. So next time I get in the car the code is gone until I floor the pedal again.

I've looked at the sensor but haven't traced the wires all the way back to the ecu. I can do that this week, just thought it was strange I don't always have the code

 

[DeMoN2318]

Do you get the code only when the car is running? try with the key in the on position but the engine off...


also check sensor itself

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=119

 

[jetjock]

..It clears itself when the car is turned off...

No, it doesn't. You're confusing codes with the MIL. Not that you'd be the first...

 

[Beefierspade]

Okay I had time to look into my harness today. From a little research the signal wire is to the brown shielded wire. So that's correct I believe.

So now moving onto the heater wires. The two black wire off the O2 are attached to a green/red wire and a black/red wire. Reading other posts the black/red wire should be a yellow/black wire.

I have a yellow/black wire that soldered to the little brown plug on the t-stat. Did the previous owner mess up or is this correct. My cars a 88 turbo.