o2 sensor

[latemevol24]

hey does any one know if the turbo and na o2 sensor is the same or are they different??
thanx

 

[yankiwi]

hey does any one know if the turbo and na o2 sensor is the same or are they different??
thanx

They are different. NA is one wire, turbo is a 3 wire.

 

[koulee]

They are different. NA is one wire, turbo is a 3 wire.

um, turbo is a 4 wire.

 

[cjsupra90]

Yeah, turbo is a 4 wire.

A turbo O2 can be used in an N/A if you hook up the additional wiring which is a sensor ground, a 12v ign. hot and another ground.

You can actually get away without hooking up the 12v and extra ground cause they are for the heater and it is not needed but is a good idea to use it though.

 

[jetjock]

4 wire eh? Must be only on the later cars.

 

[cjsupra90]

4 wire eh? Must be only on the later cars.

Why do the earlier ones only have 3?

 

[jetjock]

Mine has a three wire. 4 wires were introduced to provide a proper ground return for the O2 signal. Early Supras used a 3 wire sensor and a bonding wire from the head to the firewall. The ground reference had to go through all the gaskests and corrosion on the exhaust manifold. 4 wire is the better setup and is used on most cars today.

 

[cjsupra90]

Yeah, I know all that, I just thought that the early one were 4 wire also. didn't realize that they were 3.

 

[cjsupra90]

Actually, I stand corrected, the later ones are only 3 wire also. Dont know why I was thinking that they were 4, either way, back to what I said before, the Turbo O2 can be used on the N/A as long as you hook up the sensor output wire and not one of the heater wires, but still a good idea to use the heater circuit.

Even better, hit up an auto parts store and get a bosch universal 4 wire and wire up the heater circuit and run the sensor ground to good ground point by the ECU.

BTW, Polarity does not make a differance on the heater circuit

 

[jetjock]

Ok, fair nuff. Since you backed koulee up I thought I'd better hedge my bets since I haven't seen many of the later Soups. I agree the heater should be used, both for quicker warrm up and to prevent the "falling out" of closed loop that sometimes occurs at idle.

 

[yankiwi]

Hmm, I have never personally seen a 4 wire sensor on any supra.

I answered the guys question, and funnily enough about 5 minutes before I did I had just finished replacing my O2 sensor.

I'm not the best at math but I am pretty sure I only soldered 3 wires:biglaugh:

 

[latemevol24]

awsome thanks for the help everyone.

 

[cjsupra90]

yeah, the turbo's all have 3 wire units, my mind was off in la la land cause I was thinking about my car which had a 4 wire but I had forgotten that I had changed it to a 4 wire inplace of the 3 wire.

Like I said before about it being a good idea about using the heater circuit and jet brought up a very good point about idle closed loop drop out. This is a common problem on turbo cars and is why toyota used 3 wire units on the turbo but only a single wire on N/A's. The turbo sucks up and dissapates a lot of heat at idle so there is a very good chance that of loosing enough that you dont get the (IIRC) 600*F temp minimum needed for the O2 to opperate

 

[latemevol24]

im going turbo with my na using the turbo electronics but wasn't sure if i would need a new o2 sensor or if i could use my na one.

 

[cjsupra90]

well you could use the N/A one if you wired it up correctly, but you will get a MIL (check engine light) with a O2 heater circuit malfunction. (I dont remember what the code is though).

Best bet, get the correct O2 and eliminate any potencial problems.

 

[latemevol24]

ya i'll probly just get a new o2 sensor. it never hurts to get new parts

 

[koulee]

Coulda swore the turbo was a 4 wire. My bad.

 

[BorHor]

I'm going to change my O2 sensor tomorrow. I hope I get better gas mileage. I don't think I even hit 200 miles on my last tank :cry: