Toyota MR2 Message Board - View Single Post

geno_mr2sc · 07-15-2009, 05:47 PM

Symptoms:

ECU Code 21. Cannot clear it. Runs OK but could be better.

O2 circuit voltage seems quite low: .1 - .2v at the Af hole in the diagnostic connector.

Same low voltage exists on both sensor wires that are not heater wires when car is on. OX port on ECU sees .9v - 1v.

I have a parts car, so swapping parts is pretty easy. I have tried a different Oxygen Sensor and a different ECU.

Wiring is a possibility, but it would be the first time wires went bad on this car.

07-15-2009, 05:47 PM	#1 (permalink)
geno_mr2sc No Skills Join Date: Jul 2009 Location: Flyover Zone Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Oxygen sensor Symptoms: ECU Code 21. Cannot clear it. Runs OK but could be better. O2 circuit voltage seems quite low: .1 - .2v at the Af hole in the diagnostic connector. Same low voltage exists on both sensor wires that are not heater wires when car is on. OX port on ECU sees .9v - 1v. I have a parts car, so swapping parts is pretty easy. I have tried a different Oxygen Sensor and a different ECU. Wiring is a possibility, but it would be the first time wires went bad on this car.