O2 Sensors

[AktionCat]

So I was pretty sure I saw a thread that said exactly which is bank 0 and which is bank 1. If I remember correctly Bank 0 is closest to front of car while Bank 1 is the one right before the cat. Can someone confirm this as I'm about to change one.

[01blackG]

So I was pretty sure I saw a thread that said exactly which is bank 0 and which is bank 1. If I remember correctly Bank 0 is closest to front of car while Bank 1 is the one right before the cat. Can someone confirm this as I'm about to change one.

Honestly if your going to replace one of the 02 sensors just replace them both. Thats if you have an inline 4 cyl. Cause if you need to replace one it is pretty safe to say the other one is right behind in need to be replaced.

[Sleepervr-4]

No such thing as bank 0. If you have a i4 front sensor closest to the manifold is bank 1 sensor 1 and the one by the cat is bank 1 sensor 2. If you have a v6 then you have bank 1 and 2. Bank one is usually the cylinder head that is closer to the front of the motor. Bank 2 is closer to the back. Usually you can just look at the intake manifold runner that is closest to the front of the motor and the direction of the first runner will tell you which bank is 1. Also there is no need to replace both since the sensor 1's control fuel. The sensor 2's only monitor the cats.

[AktionCat]

OBDII check only said Bank 1.

[DTP]

Just go ahead and replace both of them at the same time... Since you're already down there.

[Sleepervr-4]

Ok you have an I4 so you only have bank one. Just noticed that you have a after market header. If you removed the front cat then even if you replaced the sensor you would have the same problem. Since there is no change in values between both o2 sensors due to the missing cat. You probably need a 02 simulator for the rear sensor to solve your cel problem. If your obd2 scanner does data look at the values for both o2 sensors and make sure they are working properly before you waste your money on new sensors. There is a thread over on club 3g for people that installed headers and need to install the rear simulator to get rid of the cell.

[Isaurio]

I have obx headers and I don't have a cel or o2 problem. What I did I took it to muffler shop and told them I need it a adapter for a o2 sensor after the main cat. This way it would read the fuel mix ratio after the cat since if you leave it on front of the cat with aftermarket headers the o2 on the precat and main cat would have the same readings. I have some pics.

Factory o2 spot I put a cover for it


New spot after the cat

[AktionCat]

The Cat I bought came with 2 bungs for which I can place a sensor in but their plugged because there's holes already for the plugs.

It was working fine but ever since it got cold here it's been putting out like..Warm up Catalyst Error..or something close..
I'll hit advanced auto parts this time and see what their OBD says.

[Isaurio]

Yeah I have magnaflow full cat back exaust system and a hi flow cat

[AktionCat]

YESsir Advanced's OBDII says Bank 1 only..nothing else..I'll prolly do what Isario has and cover the stock o2 hole right before the cat(on the OBX header pipe) then use the farthest hole on the cat I bought for the rear o2 sensor..then the front will be in it's default spot.

[Isaurio]

Yeah I have no problems with that setup. Also i put an extra oval cat right before the hi-flow cat to quiet the sound down. I belive after that i'm getting a better reading from the o2 sensor and for some reason is performing much better. I belive it has to do with the back preause too.