O2 Sensor and turbo for 3SFE?

[almc2242]

The 3SFE engine that I have has two O2 sensors on the exhaust manifold. One, then another one almost together. I was told that one measures the O2 temp or mixture. Then the next one just keeps track the the first one is working properly. It goes on a rather large, kind of Elephant Leg Manifold. I was told it's a Catalitic Converter [?].

Since I'm going turbo, what do I do with them? One is a must be install but what about the other one? I was also told that if Idon't install them the CHECK ENGINE light will go on.

Bottom line is: What do I do with them, and how do I install them so that the CE light won't come on? Is their a part on the market that will solve this delema?

[88 LE]

Originally posted by almc2242
The 3SFE engine that I have has two O2 sensors on the exhaust manifold.

Pre and post cat O2 sensors.

The 2nd O2 sensor (post cat) checks for a difference between itself and the pre-cat O2. This is to verify that the cat is working.

Bottom line is: What do I do with them, and how do I install them so that the CE light won't come on? Is their a part on the market that will solve this delema?

The 1st O2 sensor (pre cat) gets installed on the downpipe right after the turbine outlet from the turbo.

You need a O2 sensor simulator for the 2nd O2. This fools the ECU into thinking that the 2nd O2 (post cat) still exists, so it won't trip the CEL.



Another option is to install a aftermarket high flow cat. If you do this you won't need the O2 simulator.

You'd have one O2 at the downpipe and another after the cat.

[almc2242]

If the wire length of the O2 sensor is changed, will this affect the signal to the OBC? Let me explain: When I install my Custom Turbo system. I know that I have to reposition the two O2 sensors. One, just after the turbo exhaust outlet. The other one will have to go AFTER the Catalytic Converter. How long will it be reposition, is my guess. But I think the close as posible because of this wire. Any advice?

[88 LE]

Originally posted by almc2242
One, just after the turbo exhaust outlet. The other one will have to go AFTER the Catalytic Converter.

Yup, the 2nd O2 sensor goes after the cat.

How long will it be reposition, is my guess. But I think the close as posible because of this wire. Any advice?

How much you need to lengthen the wires depends on where the cat is.

But lengthening the wires on the O2 sensor is not a problem.

[white90dx]

I just left the second O2 sensor off the car and live with the check engine light. I just check it periodically to make sure no other codes are stored.

The stock ECU is only going to be in my car until I get a full standalone ECU anyway...

-Charlie

[almc2242]

Well, in my case. I'm getting the E-manage. I think this might solve the problem, am I correct?

[white90dx]

Originally posted by almc2242
Well, in my case. I'm getting the E-manage. I think this might solve the problem, am I correct?

The Emanage is only a piggy-back computer. If you don't take care of the O2 sensor signal somehow, you will still get the check engine light.

-Charlie

[almc2242]

I guess I'll just put an extension O2. I saw it on the fame 5SFE Camry from Brian toyota in Seattle.One for next to the exhaust and the other right before the Cat Con

[white90dx]

Originally posted by almc2242
I guess I'll just put an extension O2. I saw it on the fame 5SFE Camry from Brian toyota in Seattle.One for next to the exhaust and the other right before the Cat Con

You will want to put the second O2 sensor AFTER at least 1 cat... otherwise you will get the check engine light.

-Charlie

[almc2242]

Roger That. What was I thinking when I made that typo

[white90dx]

[theDogg]

turbocharging a 3s-fe is not the smartest things to do. if ya wanna fast engine get the 3s-gte. reliability on the 3s-fe goes to hell after forced induction. the best for 3s-fe's are complete exhaust system and air intake replacement. other than that the reliability of your car is not gonna be all that great. It wont even be that much faster either. FWD cars don't like too much power!!

[almc2242]

I've seem many RAV4 with turbo in Japan and OZ and they kick asphalt, 2WD and 4WD, using the 3SFE engine. Many Camrys also.
Some RAV4s are 3SGTE, but to install one of these is Hell. Just a simple Turbo kit with Intercooler will work fine. Of course you should re-enforce them with Performance Oil pump, and Water pumps. Other then that the 3SFE is fine. If not, why did Toyota install this engine in the MR2?