Hi All,
I'm new to the forum and have to say i love it so far. It is very informative and friendly one.

Yesterday, i finally got the chance toscanthe "Service Engine Soon " on my 2003 Montero Sport Limited with a 3.5L engine and i believe all i got are four are errors for my O2 sensors and they are as folows;

1 of 4 - PO161 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)
2 of 4 - PO141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
3 of 4 PO161 O2 Sensor Heater Circuit Malfunction (Bank2 Sensor 2)
4 of 4 PO141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

I'm i correct in assuming that i need to replace all Four(4) of my O2 Sensors and that there is actually 4 units that i need to replace. Can you also please let me know the exact location of these sensors(tried searching and can't seem to find an answers). I am the first owner and i know for a fact that none of these have been replaced.

In addition, I also read about a TSB with regards to "Diesel Engine Sound" when the truck is on idle, Will the dealer be able to eliminate this sound if i bring to them for service and is this still covered by the warranty.

I apolgize if i asked too much for a first timer but i really like to bring my truck into shape.

Thanks.

 

If it's still under warranty, then I would doublecheck the terms of your warranty. I'd expect both problems to be covered.

 

I'm trying my best to locate the 4 pin plug that terminates O2 sensor on passenger side aft; (bank 2 sensor 2)-- the Mits. dealer parts diagram is totally useless for location... Can anyone help?!?
Thanks, gewaddy

 

I have two Mitsubishi's.

2004 Endeavor
2003 Montero Limited

It sounds odd, that all your sensors are out, but I have replaced 2 on my
cars.

First off, most dealers and parts people DO NOT know which sensor is which.
On my Endeavor, since the engine is mounted sideways, every "expert" was
seemed confused about which Bank was which.

Here's my advice.

Take an O2 sensor off. The easiest one.
You may need a special socket. I got mine at PEP Boys. The one I bought at AutoZone didn't work with the Bosh replacement sensor they sold me.
Bring your socket with you if you have one, or test the one you buy with the
sensor you buy!

Replace the sensor.
You will need to drive the car around 10-20 minutes.
The have re-scan the codes. You should have one less Error Code.

If so, pretty good chance all your sensors are bad.

This is my experience

 

Umm, aren't there only two bad ones, look closely. Bank 2 sensor 2 and Bank 1 sensor 2, the codes are repeated!

 

o2 senor code p0155 2004 Mitsubishi Endeavor need to be replaced I can work on cars. can someone please send me a picture of the area of where I can find and replace the sensor? thank you