will this sensor trip on the header?

[Dawgz]

Here is my pre-cat header (front)




notice how there is a sensor, but before the pre-cat..., now if i swap this header out with the non-precat header, will this sensor u see trip a CEL? no right because its a bit before the pre-cat...


as for the rear header, the pre-cat for the rear header is on the ypipe's pipe for the rear header, not the header itself.


I asked Dat this already, and got his opinion, i want to see what u guys think as well.

[Dawgz]

Someone told me that i might need to swap out my ECU to the non-cali spec ecu...

is that true? why would i need to do that if i can just get a o2 simulator ?

[Dawgz]

heres a pic of the ypipe diffrence, notice how u can clearly see the pre-cat for the rear header on the ypipe on the cali spec ypipe...

[Eye8Pussies]

if the sensor is before the pre-cat, then it won't make a difference

that 02 sensor is used to monitor the a/f of the front bank (physically the front bank, but technically the rear bank according to toyota if I remember correctly) for the ecu to do its tuning with

you may end up needing an 02 simulator for the secondary post-cat sensor though, as your single cat (or high flow cat that you might get) may not clean the exhaust enough to satisfy the cali-spec ecu

[hskrsolara]

just get an o2 simulator and instead of just wiring the rear sensor, wire both front and rear sensors to the simulator.

[Dawgz]

if the sensor is before the pre-cat, then it won't make a difference

that 02 sensor is used to monitor the a/f of the front bank (physically the front bank, but technically the rear bank according to toyota if I remember correctly) for the ecu to do its tuning with

you may end up needing an 02 simulator for the secondary post-cat sensor though, as your single cat (or high flow cat that you might get) may not clean the exhaust enough to satisfy the cali-spec ecu

There is a post cat sensor? where? i thought id need a o2 simulator just for the sensor after the cat, the one on the mid pipe...

[hskrsolara]

you may need 2...one for each o2 sensor. I'm not sure if you could just wire both o2 sensors to the same simulator, but this would be easier if possible. however, i would think this would create some problems with cel's since the current draw could be different.

[hskrsolara]

I would contact URD and ask them.

[Dawgz]

i dont understand where the other sensor is...im only thinkn of the one after the Main Cat, wheres the other one? on the Front header i have in the pic?

[bassthrive]

i believe the sensors on the front and rear headers are both a/f sensors. the one post-cat is o2.

[Dawgz]

i believe the sensors on the front and rear headers are both a/f sensors. the one post-cat is o2.

they wont trip a CEL if i swap the headers rite? judging by the picture i posted.

[Akfahad]

^^^contact your local dealership and find out whether or not the sensors on the headers are 02 sensors or A/F sensors. If A/F sensors, then no worries.

[SC V6]

that front sensor controls how much the computer leans out the fuel ratio or makes it richer. I would think that removing the first "pre-cat" wouldn't do anything. There is a sensor after the actual cat, which would need to be in place, but I think the "pre-cat" is just to be overkill since its Cali spec.

I bet you wouldn't have issues with swapping the headers out (or gutting the pre-cat), just so long as there are 3 o2 sensors total (one on head header, and one after the cat on the midpipe)

[SC V6]

now that I Think of it.. u might have issues with the actual cat sensor (on the midpipe) since the constraints of the computer might be more agressive.. just get an o2 simulator for that one..

www.o2simulator.com

they have cheaper sensors then what i've seen around

[Dawgz]

^^^contact your local dealership and find out whether or not the sensors on the headers are 02 sensors or A/F sensors. If A/F sensors, then no worries.

he said the the sensor in the back header is a o2 sensor (there is no precat on that header, its on the ypipe itself, u can see it in the diagram i posted above)

and he said the front header has a A/F Sensor.