stanz

iTrader: (1)

I'm installinga LC Engineering header tomorrow and from everything I read, I should expect my CEL to go on as the O2 sensor will be located too far downstream for it to read properly.

I understand that a heated (4 wire) o2 sensor is the remedy.

I'd prefer to go with a 88-89 4Runner Denso 4 wire O2 sensor to minimize other issues with universal or non-OE (i.e., Bosch).

I've searched up and down here and on Google for over an hour and although I found lots of information, I am unclear of the following...

One of the wires will go to the existing stock single o2 sensor lead (which color on the 88-89?)

According to LC using a Bosch universal, there are two grounds and a heated wire that goes to a switched circuit.

Would the same be true if I use the 88-89 sensor? I saw schematics (that I'm not the best at reading) suggesting a second wire going the ECU.

I'm super confused. I just need to understand what color wire goes to what.

Thanks in advance!

stanz

iTrader: (1)

Thanks to 4Crawler's page, I think I found my answer:

-Blue Wire goes to the original Black signal lead
-White Wire goes to Ground
-Two Black wires (doesn't matter if reversed):
*Switched 12v for heat element (draws 3-4 amps)
*Ground

SoCal4Running

I've never had a 02 fault issue on my 86 with the same header.

I just the factory Denso sensor. Plug and play.

EDIT: just saw in a different thread you say they put the sensor at the cat?
This is not correct for a first gen. Mines at the Y of the 3 and 4 cylinder.

stanz

iTrader: (1)

Yes, mine will go right in front of the cat.

Philbert

iTrader: (2)

The O2 sensor goes there if you have the OEM header. He installed the LCE header, which relocates the O2 sensor bung closer to the CAT, hence his question.

Stanz - this is interesting - I never came across this info until now and I have had the LCE header and pro flow exhaust for 4 years. I've had some close calls with smog in CA and both times they tell me to try and get it hotter and test it immediately if possible - wonder if this is why (I am running the non heated O2 sensor....).

stanz

iTrader: (1)

Sounds like the same issue.

I'm a geek about clean installation so I found the female plug end and pins here to make it all clean and plug and play in the future:



http://www.chasebays.com/product/con...r-4p-connector

imfoolishyet

I had the same issue that was completely resolved by installing a heated O2 sensor. I purchased the cheapest universal sensor that came with the necessary flange adapter for toyota.
A document such as this hiflo.com.au/pdf/O2%20sensor%20wiring%20colour%20codes.pdf‎ can assist if you acquire a sensor without a wiring diagram.
I connected the heater power line through a relay using the Idle Air Control (old style, not on throttle body) power line as a trigger.

edit- It appears that the link won't work. You can find it if you google search "O2 SENSOR WIRING COLOUR CODES"

stanz

iTrader: (1)

Awesome to hear. I will go the later gen OEM route, but do the same wiring. Thanks for sharing!

stanz

iTrader: (1)

I just ordered off of Amazon. Fits a 1993 4Runner and it mates up to the harness plug I ordered from Chase Bays. Hoping this all does the trick.

SoCal4Running

My bad guys I got the Downey header. Sorry

stanz

iTrader: (1)

Update: I have the header installed and the heated 4-wire O2 sensor installed. It's running better than ever. No issues, no CEL. Super easy install for the O2 sensor. See my build thread for pics.