I have a truck that I am swapping a 3.4l into. I am running true dual exhaust so there is no Y-Pipe or catalytics converters. Do I need to run two O2 Sensors? and if i do where would be the best place to find them for good price?

 

The ECM uses one sensor to adjust the fuel trims for both banks. If you only run one sensor, it's input will only come from one bank. I would try to run an X-pipe at least and put the sensor there, but it's got to be pretty close to the heads...I'd say not more than 2 feet downstream or else the readings may be screwed up. For the post cat sensor, you can get one of those simulators that they sell at jegs.

Why not run a single exhaust? This ain't a small block chevy, it's a toyota.

 

Thanks for the info. I was going to run the single exhaust but the crossover pipe would not fit because of where the motor is mounted. I also have not seen a truck that runs true dual exhaust so i wanted be unique and see how the truck runs and sounds.

 

I'll take some pics of my setup tonight...I made the crossover come underneith the bellhousing.

I've also got a set of Downey headers for sale if you don't feel like building stuff.

 

Very cool I'll take a look tonight. Another question if I'm not running a catalytic what should i run for an after catalytic o2 sensor because it wont read a difference because there is no cat. So should i run two of the pre-catalytic o2 sensors or should i get an o2 sensor simulator and run an after catalytic sensor?

 

I would like to know where to get the Sensor simulator??

 

Sorry to dig up the old thread...

I'm now thinking of not using the behind the engine cross over, however placement of the first O2 sensor in my design would only be reading the 3 cylinders on the drivers side. Is that really a big problem? (95 T-100 ECU, with 2nd O2 sensor simulator)

Thanks!

 

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