svdude

iTrader: (3)

So, I bought this 88 4runner that originally had a 22re motor in it. The p/o did an rte swap and put a big ol t4 turbo on it. I pulled the big turbo off and am putting it back to stock.

Here's my dilemma, there is an o2 sensor port on the downpipe from the turbo. Obviously the 22rte 4runners had an o2 sensor there. But I pulled the o2 sensor off of the previous exhaust from behind the driver seat area of the undercarriage.

So I guess my question is: Am I missing an o2 sensor (one before and after the cat) or was there originally only one o2 sensor past the cat on the 22re setup? If there's only one sensor then I can just relocate the one that I have. If there is supposed to be two of them how would I go about installing another and wiring it up correctly?

sam333

There is always an o2 sensor before the cat( on all cars/trucks that have o2 sensors) sometimes one after the cat, sometimes not depending on the make /model/ year.The first o2 sensor keeps the air /fuel ratio in the proper range , the second just tell the computer that the cat is or is not working properly, but has no affect on the engine operation.

svdude

iTrader: (3)

So I am definitely missing an o2 sensor then. When I pulled the other turbo setup out, there was not a cat installed. The dude made a 4 inch exhaust system with no cat... and only one o2 sensor. How would I go about wiring in another o2 sensor, more importantly, what is the importance of having an o2 sensor before the cat?

smrflng

As far as i can remember the 22re's had an o2 sensor either in the exhaust manifold or just in front of the cat. It depends on the year of the vehicle. It seems if memory doesn't fail me the earlier ones were in the manifold and later just before the cat. at least that is how all of mine have been. But then again I did use a universal o2 sensor with a bung welded into a header on my '85.

Russ

sam333

The o2 sensor is there for emissions ,it tries to keeps the air /fuel ratio at a about 14.7 to 1. It does this so the cat can burn off any CO, HC, Nox thats left in the exhaust. The o2 sensor has an enough of an effect on the way the engine runs that you cant run without it.You would be running in open loop ( pre programed fuel setting) rich all the time .You would have lower fuel milage and probably would not pass smog.

sam333

By before the cat , I mean ANYWHERE in the exhaust stream between the header and the cat, so as to control air/fuel mixture.

svdude

iTrader: (3)

How do I wire in another o2 sensor? I have the oem one hanging from a boot under the driver seat area but I just looked again and there isn't one tucked anywhere near where it should be in the engine bay.

svdude

iTrader: (3)

Or better yet, can someone follow their first o2 sensor and tell me where the wires go? The guy who did this motor swap didn't really do the 4runner a whole lot of justice, imo. I have had to do quite a bit of work to put it back to stock.

tried4x2signN

There is more to an "rte swap" that just bolting on a big ol Turbo on it.

You might better check and see if it's got a 7:5.1 compression ratio before you go naturally aspirated...

Then, you need to see if it's got RTE electronics...

You might just have too big of an exhaust...

What's your problem with it now?


PS, T4 doesn't exactly mean it's big. There is a lot to a Turbo that I don't know, but I do know there are wheel sizes and ratios.

THAT denotes if it's big and requires a lot of C.I's to push.

sam333

Look at a wiring diagram for your year model.

svdude

iTrader: (3)

It does in fact have the rte motor and the rte ecu. But the turbo that was on it was way too big and the motor was hitting fuel cut off because the turbo was too big for the stock fuel system. I wasn't to put it back to stock so here I am now. I just don't know how to go about putting the 1st o2 sensor in. I was hoping to see some capped wires or an empty plug somewhere that I could just install the sensor, but no luck.

myyota

The 85-88 trucks turbo or otherwise only have one 02 sensor, and it needs to be installed in the propper place in the exhaust system for it to function properly. So find the propper location for the 02 sensor thats on your truck and have an exhaust shop install it for you. Again, your truck only has one 02 sensor, not two.

svdude

iTrader: (3)

Exactly what I needed to know! Can I just extend the wires from the 22re o2 sensor and plug it in or do I need to have a sensor off of the rte harness?

annoyingrob

You can just extend the wire.

svdude

iTrader: (3)

Well, I found the O2 sensor plug. It's the yellow plug that was just sitting on top of the engine.

I'm sure a lot of you are getting a good laugh right about now. I was doing continuity tests on all the black wires coming out of the harness to find which one was the O2 sensor wire. Well, the wire at the ECU is a black wire, it changes to a gray wire in the harness... all this time I have been looking for a black wire for an O2 sensor connection.

Oh well, my harness is much prettier than it was before and I didn't have to cut into any wires at all

svdude

iTrader: (3)

btw: I don't know anything about engines, I'm learning as I go. At least I try and do my research before I mess something up.