1FZFE O2 Sensor Wiring (1 Viewer)

[YotaVincent]

Recently bought my first 80 and have been battling this CEL for the O2 sensor, bank 1 upstream. Upon going under the truck I learned somebody installed a universal O2 and got rid of the pig tail connection and just butt connected the wires together. I ended up getting an Denso(OEM) O2, and cant seem to get the wires correct.
Truck side:
Yellow with red stripe
Blue(protective seething around it)
Grey
Red(brownish) with black stripe
O2:
Black
Black
White
Blue
I installed as following.
Blue-Blue(signal?)
Grey-white(ground)
Yellow/red-black(heater)
red/black-black (heater)

My question is did I wire this correctly? I still get the CEL

 

[ppc]

What year is your vehicle?

You should go into your profile and add vehicle specific information to your signature. That will appear at the end of each post you make. That provides other forum members the info that is needed to respond better to your questions.

 

[YotaVincent]

What year is your vehicle?

You should go into your profile and add vehicle specific information to your signature. That will appear at the end of each post you make. That provides other forum members the info that is needed to respond better to your questions.

Just updated that, thanks Phil,

Its a 1996.

 

[ppc]

Here is the wiring diagram from the FSM:

 

[YotaVincent]

Here is the wiring diagram from the FSM:

View attachment 1972353

I see all the colors there, perfect. I cant tell whats a heater, signal or ground though. If i had to predict the Brown/Black wire is the ground. Yellow/red is the signal? Blue, and Grey are heaters..?
BR-B = brown red
Y-R = yellow red
L= Blue
GR= Grey

 

[ppc]

OX1 and OX2 are the signal wires
HT1 and HT2 are the grounds for the heater circuits with the Y-R as the power source
E1 would be the common side for both signal grounds

These are the wiring color codes:
Wire colors are indicated by an alphabetical code.
B = Black, L = Blue, R = Red, BR = Brown,LG = Light Green, V = Violet, G = Green,O = Orange, W = White, GR = Gray, P = Pink,Y = Yellow, SB = Sky Blue
The first letter indicates the basic wire color and the second letter indicates the color of the stripe.

 

[YotaVincent]

Well I guess I need to figure out the Denso side of things. Figure what each color denso means now.

 

[ppc]

If the new sensors were OEM replacements and had the correct connector just match the pin numbers to the diagram. Obviously the two blacks are for the heater where polarity is not required.

 

[YotaVincent]

If the new sensors were OEM replacements and had the correct connector just match the pin numbers to the diagram. Obviously the two blacks are for the heater where polarity is not required.

Im trying to understand the diagram but wiring is not my strong suit. I think the L(blue) should match the blue on the new o2. You're saying the Y/R is the power source for the heater, and HT1(GR) which would go to my blacks, polarity not mattering. That leaves the BR/B to the white on the O2...

Is that what youre saying? Im also going to use your recommendation about the pin numbers.

 

[ppc]

That seems to be the case but you indicated you still had a CEL. Have you manually cleared the CEL?

 

[YotaVincent]

That seems to be the case but you indicated you still had a CEL. Have you manually cleared the CEL?

I had it wired up a different way, just wired it this way. Going for a test drive!

 

[YotaVincent]

Back from test drive after doing "Toyota Drive Cycles" as stated in the FSM, CEL popped again! UGH! This time for P0401. On my way out to test my VSV and EGR with a vacuum gauge.

 

[YotaVincent]

For the record O2 is now wired correctly and not throwing codes anymore.

P0401 solved now with new EGR VSV, EGR Modulator, and all new vacuum hoses.