Waz996

iTrader: (1)

I know this might sound a bit strange, but to my knowledge the O2 sensor in US cars is located somewhere before or after?) the catalityc converter under the car? I am in the process gettin a full exhaust system (down-pipe+cat delete+full cat back exhaust) and i was wondering whether the 02 sensor location in our Gulf spec car is otherwise..

I took a picture to clarify my point..



Is this the 02 sensor in my car or am i wrong? Should i search elsewhere?

Sorry for my inexperience but I'm lost..

Thanks

Wael

DrSmile

iTrader: (2)

There are TWO. One where you are pointing, the other behind/in the cat. The one that trips the cel if you don't have a cat is the rear one.

Waz996

iTrader: (1)

Is the one i am pointing at located in the 'downpipe' section or on any section before the downpipe? Because i am planning to have a Perrin Downpipe as well..

Thanks for your answer//

Wael

EnJaNir

iTrader: (4)

The primary o2 sensor is located in the o2 housing which the downpipe bolts to.

The secondary o2 sensor is located either a) in the bpipe (VIII) or b) in the cat (IX)

Jussb1aze

iTrader: (6)

It should be before the downpipe, like in the o2 housing i believe

Waz996

iTrader: (1)

OK.. I went down again and took the picture of the secondary sensor.. Goes right on top of the cat on the very upper front neck (that's why i couldnt see it before)

Funny, my old jap evo7 didnt have a sensor in this location at all!! that's why i am surprised..

OK, so the next question: If and when i get my perrin test pipe, i know it comes with an O2 simulator.. So I undrestand i have to fix the sensor and the simulator as well (as shown on a small sketch on the net - evomoto.com)

Thanks for replies everyone! Relieves many doubts!

Wael

Waz996

iTrader: (1)

this is the secondary sensor in my car..

Boosted GP

your car is the australian/euro/ south african spec, where the second 02 sensor is located before the MAIN cat. you "MAIN cat"??, yip our cars have a small cat in the Down pipe, and then the second or main cat is under the car. this second 02 sensor is placed before this second cat, where as the US spec'd cars have the second 02 sensor about 20" (500mm) further down the exhaust.

you will also see that the o2 sensor wires go up into the car before the cat, and you will find the wires in front of the gearlever consol (about in line with the radio under the side cover of the center consol, on the right side) not under the center arm rest as on the US spec cars.

if you order a test pipe, you will need to ask them to either weld a bung in it or ask them to ship a o2 bung for you to weld in as the US cars DO NOT have a sensor there and thus the test pipes have no bung welded into them.

I have the WORKS DP and RTP, and I had to do this.

Mike

Waz996

iTrader: (1)

Hey Mike! That's a lot of info here!!

I think you made a mistake in your write up saying 'the US car dont have a sensor there'. I think u meant 'the Euro cars dont..' Which makes me to beleive that i have to place a bung (a cork sort of) to close the hole with which the US cars would close with their sensor at that location.. ok i understand!

I am going for the Perrin test pipe wihch comes with an O2 Simulator, which i do understand where the location of the wires are, according to your description..

My question is: where do i put my sensor since there wont be any hole? Do i leave it dangling in the open and use the 02 Simulator to fake it? Do i open a new hole in the location of our Euro cars and place the second sensor there..

mind you, I am going for a perrin DP as well, which will also delete the 'first' cat that my car has, being a euro model..


Please correct me if I am wrong!!?


Wael
*another sleepless night full of worries and doubts biting my fingers waiting for an answer!!*

Boosted GP

What I am saying is that: ALL evo (evo 8 and 9, not sure about earlier models) have the first sensor just after the turbo (your first pic with your arm in it, by the radiator) this is used for control of fueling by the ECU in closed loop senarios.

the second sensor in our cars (the euro/Aus/south african) spec cars have the sensor placed as in your second picture (at the end of the down pipe). they place this sensor here so that it gets a quicker response on startup of the car for european regulations (hence the cat in the DP, also for quicker response on managing emmisions for euro regs) but in the US there is no cat in the DP so the sensor under the car (where our second cat is (the big one)) so the second sensor needs to be after the main cat, it cannot be before otherwise it would throw an error all the time. The sole purpose of the second sensor is to show that the cat is doing its job (has nothing to do with engine fueling control), thats why it throws an error when we remove the cat.

I'll try find a pic of where the second sensor fits in the Intermediate pipe.

the sensor on our cars actually sits after the DP/cat flange in the cat section of the exhaust therefore if you order a perrin test pipe, you will need to get a bung (threaded tube to screw the sensor into) welded at the front of it as you cannot leave the sensor hanging. all the o2 sim does is modify the signal to the ecu from the sensor, but the sensor still needs to be attached to the exhaust so it has an earth connection.

Mike

Waz996

iTrader: (1)

Mike, you're great! Thanks a lot!

Wael