O2 sensor help

[M-Piers97]

I got my CEL codes ran today and the stealership said i have a bad O2 sensor part #89465-39855 B1 S2 (Bank 1 Sensor 2?). I want to know is this the upstream or downstream O2 sensor? and would a bad one cause any problems (misfire, bad MPG's etc.) Is it worth replacing? Thanks

 

[Buckaroo]

Sensor 2 sounds like downstream. Do you have 3.4Lv6? If downstream, only downside is it may light up your MIL. Does not control, only monitors. So, if you don't have to pass emission test - no worries. A bit of concern having your MIL lit all the time as you can't see new issues w/o some kind of scanner.

 

[TheDurk]

I got my CEL codes ran today and the stealership said i have a bad O2 sensor part #89465-39855 B1 S2 (Bank 1 Sensor 2?). I want to know is this the upstream or downstream O2 sensor? and would a bad one cause any problems (misfire, bad MPG's etc.) Is it worth replacing? Thanks

Sensor 2 is the downstream sensor after the cat. The dealer will charge you an arm and a leg, but you can get the same sensor on Amazon and do it yourself for much less.

Go here: Find My Part | DENSO Auto Parts and cross that number to an OEM Denso part number and buy it on Amazon or RockAuto (Denso only!!!) and do it yourself.

The only thing the rear sensor does is set codes for itself and for the catalytic converters. No effect on how the car runs, at least in the short-term. Theoretically, the ECU uses the rear sensor to recalibrate the front one, so over time there may be some loss of precision in engine management. The main reason to replace it is to make the codes go away--mandatory for those of us with emissions inspection.

 

[M-Piers97]

Sensor 2 is the downstream sensor after the cat. The dealer will charge you an arm and a leg, but you can get the same sensor on Amazon and do it yourself for much less.

Go here: Find My Part | DENSO Auto Parts and cross that number to an OEM Denso part number and buy it on Amazon or RockAuto (Denso only!!!) and do it yourself.

The only thing the rear sensor does is set codes for itself and for the catalytic converters. No effect on how the car runs.

Sweet, thats what i wanted to hear. The stealer wanted to charge me $130 to do it and i know i can get a sensor of ebay for $30 bucks an install it myself

 

[M-Piers97]

Sensor 2 sounds like downstream. Do you have 3.4Lv6? If downstream, only downside is it may light up your MIL. Does not control, only monitors. So, if you don't have to pass emission test - no worries. A bit of concern having your MIL lit all the time as you can't see new issues w/o some kind of scanner.

Yep its a V6 3.4 5VZ. I think i am going to just leave it alone, no sense in replacing it if its not going to affect anything

 

[T4R2014]

This isn't something that costs a fortune; it's like $60. I noticed better MPG's when I replaced mine.

 

[TheDurk]

This isn't something that costs a fortune; it's like $60. I noticed better MPG's when I replaced mine.

From a rear sensor? I'd be surprised. Front sensor, absolutely.

 

[T4R2014]

From a rear sensor? I'd be surprised. Front sensor, absolutely.

Fair argument. I replaced both of mine at the same time so I can't give any info.

 

[M-Piers97]

Fair argument. I replaced both of mine at the same time so I can't give any info.

That does make sense........:eyebrows:

 

[swaycleveland]

Just a thought... Why don't you tell us what code you got. I'm betting your o2 sensor is just fine.

 

[M-Piers97]

Just a thought... Why don't you tell us what code you got. I'm betting your o2 sensor is just fine.

For some dumb reason that i will never understand, they would not let me take the sheet of paper home with the codes on it that I PAID FOR
:wtf:

 

[swaycleveland]

try autozone or the like they read codes for free then post you code

 

[T4R2014]

That does make sense........:eyebrows:

It does if it calibrates the front sensor. Mine wasn't even throwing codes when I replaced them. These parts just go bad over time. I heard the they can be cleaned but I never tried. Btw, try checking your code out with a local mechanic. All the ones I've gone to will check them for free.

 

[M-Piers97]

Btw, try checking your code out with a local mechanic. All the ones I've gone to will check them for free.

Sigh..... the stealership charged me $87 bucks to run the codes :sobbing::cry2::dammit:

 

[T4R2014]

Sigh..... the stealership charged me $87 bucks to run the codes :sobbing::cry2::dammit:

Don't return to that dealer. Ever. If you have an Android phone you could get the Torque app and a bluetooth adapter for $35 and be able to check your codes yourself.

 

[M-Piers97]

Don't return to that dealer. Ever. If you have an Android phone you could get the Torque app and a bluetooth adapter for $35 and be able to check your codes yourself.

No sh!t, i will have to look in that :thanks:

 

[swaycleveland]

That's what I use!