1999 Infiniti i30 Oxygen (O2) Sensor

[thoward82]

Hi,

I have a 1999 Infiniti 130 and recently the Service Engine Soon light came on. I took it over to a local auto parts shop and I was told that the O2 Sensor needs to be replaced and they indicated that it was Bank 1 Sensor 1. I have done some research on this and spent a few hours under the car making sure that I know what I am getting myself into.

I believe I have found 3 oxygen sensors but I'm not 100% sure I know the one that needs to be changed out.

I found one in the middle of the car on the exhaust (pipe) about even with the driver's side door.

I found another that is in the front of the car and has the wires that end up near the radiator/fan.

The final one is way inside the engine more on the passenger's side.

The whole upstream/downstream thing confuses me. I can post pictures if my descriptions are not clear.

Is there a diagram that would show exactly where the bank 1 sensor 1 O2 sensor is located?

Which one is the one is considered bank 1 sensor 1?

[loystock]

Based on the info provided, you car is configured under the Federal emission standard (CA emission configuration is a bit confusing).

Bank 1/2 refers to the bank of cylinders in a V6(V8) engine - Bank 1 for cylinders 1-3-5-(7) and Bank 2 for cylinders 2-4-6-(8). Since the VQ engine in you 99 I30 is Transverse (side-side as opposed to longitudinal, front-to-back), Bank 1 is closer to the firewall while Bank 2 is towards the radiator.

For Oxygen sensor location, in general, FRONT refers to sensors mounted before (upstream) the catalytic converter while REAR refers to sensor mounted after (downstream) of the converter. However, for CA-configured car, there is no O2 sensor downstream of catalytic converter - it is mounted upstream of the Precat. The Front sensors usually has 3-wire connector (Power, Signal and Ground) while Rear sensor has 4-wire connector (Power Signal. Ground plus a dedicated signal ground).

In the VQ exhaust system, the Front O2 sensors are mounted on the VERTICAL portion of the exhaust pipe while the Rear O2 sensor is mounted HORIZONTAL section - Federal configuration downstream of 'cat' while CA configuration is upstream of 'precat.

For you car (Federal configuration)1. Bank 1 Sensor 1 - front sensor mounted on the vertical portion of Bank 1 exhaust. It is also referred as "Front-Front Right O2 Sensor." This is what you need - 3-wire heated sensor @ 26" cable length or longer.2. Bank2 Sensor 1 - front sensor mounted on the vertical portion of Bank 2 exhaust. It is also referred as "Front-Front Left O2 Sensor."3. Rear Sensor - mounted downstream of 'cat.'

For OEM parts, the best place to buy is at IoS, one of NICO sponsors with 25% off MSRP - http://www.infinitipartsusa.com. You can also go to their site to get pricing info (@ $126) as well as diagram of O2 sensor locations.

However, for O2 sensors and spark plugs, best pricing for OEM and quality replacements are from "NGK.com" a.k.a. "sparkplugs.com" (@ $69)

[thoward82]

Loystock,

Thank you for your response. I don't mean to question your response, but I was speaking with my neighbor (who worked at Advanced Auto Parts for a long time) and it seems as though what he told me is exactly opposite what you told me.

Here is what he said:

If at first they said Bank 1 Sensor 1, I would be inclined to say that it is the one on the front exhaust manifold. I believe that car's V6 is mounted transversly, or sideways in the engine compartment. So you will see an exhaust manifold in front and another in back of the engine compartment. There will be an O2 sensor in both manifolds. There will also be at least one more further down the exhaust near the muffler, but it sounds like it is not that one that is the problem. Typically "Bank 1" would refer to the front manifold.

Does anyone know which advice is correct?

[loystock]

Unless your friend is a certified Nissan/Infiniti technician, then his opinion does not count. I don't think he knows anything about the VQ engine.

I have a 97 & 99 I30 CA-configuration and I know each O2 sensor location connector location and even cable length and color-coding from the top of my head. It's more complicated than the Federal configuration.

It's obvious that you don't have a copy of the FSM... here it is. Look at chapters 'ec' (Emission Control) and 'em' (Engine Mechanical).

[http://www.nicoclub.com/FSM/i30/1999/]

THE TRUTH WILL SET YOU FREE!!!

[G-justin]

i also have an o2 sensor code and a knock sensor code on my i30 and chance they are related to eachother?

[GoldFishI30]

I have a 1999 Infiniti I30 as well. Just recently, my SES light came on. I checked what it was at my local AutoZone, and they gave me the code:
P0158 Heated Oxygen Sensor 2 Circuit High Voltage (Bank 2).
I'm guessing its on the exhaust pipe, but I'm not sure which one.
Can someone tell me more exactly where that sensor is located.
Thank you in advanced!
God Bless!

[OwnerCS]

Here are some pictures of the Bank 1 and Bank 2 Sensors below with a tool.

NON-CALIFORNIA MODEL

Sensor Tool



Bank 2 Sensor 1 - Front of Vehicle



Removing Bank 2 Sensor 1 from underneath the vehicle



Bank 2 Sensor 1 Removed -- Note the threads on a new sensor should be coated with copper anti-seize



Bank 2 Sensor 1 Plug



Bank 1 Sensor 1 - Above the Drive Axle -- Passenger Side (U.S. Models)



Bank 1 Sensor 1 - With Tool



Bank 1 Sensor 1 - Plug



Old O2 Sensors -- After Removal