Rear - O2 Sensor Installation Question

[MIZZOUNNC]

My CEL illuminated and the Acura Dealership told me the rear O2 sensor was bad. They didn't tell me which one. The cost was $375.00 to fix it and I opted for DIY.

So not knowing which sensor was bad, I ordered both. The DENSO 234-4099 for the left and 234-4092 for the right.

My assumption is, the LEFT O2 Sensor is for the exhaust exiting on the LEFT side of the car if I'm looking at the car from the rear and the same for the RIGHT.

Question is, is my assumption correct?

 

[R77F1]

To be more accurate, you need to go to the auto parts store such as the AutoZone, O'Reilly Parts, Checkers, or Napa. You can either drive your NSX there or lease for free(deposit your $ to ensure you will bring it back) the ODBII program diagnostic tool. This tool will give you the codes and PM me so I can help you figure it out which one, Rear or Front?

 

[MIZZOUNNC]

To be more accurate, you need to go to the auto parts store such as the AutoZone, O'Reilly Parts, Checkers, or Napa. You can either drive your NSX there or lease for free(deposit your $ to ensure you will bring it back) the ODBII program diagnostic tool. This tool will give you the codes and PM me so I can help you figure it out which one, Rear or Front?

The Acura dealership said the Rear O2 sensor was bad. (At the time, I didn't know there were 2 sensors so I didn't ask which one. Front O2 sensors, doesn't appear to be an issue since the car's engine performance is normal. Therefore, the rear sensor's are the issue.

Back to the original question, how does one tell, which is the LEFT sensor vs the RIGHT sensor?

 

[Larry Bastanza]

The rear has two sensors as noted, one before the cat and one after. If you were to get the code, you would know exactly which one. If you purchased both and want to install them, then your issue should be resolved.

The good news is the rear is WAY less work then the front. Get a good 02 sensor wrench (Autozone, pretty reasonable), and get it scanned for free, as mentioned above, while you are there.

HTH,
LarryB

 

[MIZZOUNNC]

I know the NSX has four O2 sensors. The rear sensors are located just after the exhaust leaves the CAT converter. The question is, when I ordered the DENSO sensors they were specifically listed as LEFT and RIGHT. The prices were not the same and the part numbers were not the same. That leads me to believe they go specifically in the RIGHT and LEFT side.

So the question is, how does one know which sensor goes where. How do I tell the left from the right?

 

[Larry Bastanza]

The position is only there to designate the length of the cables. They are all the same sensor. So as long as you match the cable length, you are OK.

Many times I have used generic 02 sensors, that come with pigtail wires, and I splice them into the original cables. The generic 02 sensors are not "location specific" so I know that all four are the same.

HTH,
LarryB

 

[ffffanman]

ok, I think i know what he needs, beside a swift kick in the a$$ for talking to my friend Larryb with that tone!!! lol, Just kidding.
When you stand on the passenger side of the car looking across the engine bay to the drivers side, then the right side is the front, and the left side is the rear. Hows that???
Things are always viewed from the crank pulley side of this motor.
This is just my belief and opinion and may be wrong.
The cylinders are also numbered this way as 1,2,3, going away from you on the left or rear and then coming back to you on the right side 4,5 and then 6 nearest you and the passengers head.
Now if I'm wrong, I'm the fool. lol
Have a great day and good luck.
Trev

 

[MIZZOUNNC]

The position is only there to designate the length of the cables. They are all the same sensor. So as long as you match the cable length, you are OK.

Many times I have used generic 02 sensors, that come with pigtail wires, and I splice them into the original cables. The generic 02 sensors are not "location specific" so I know that all four are the same.

HTH,
LarryB

That's what I needed to know.... Thanks LarryB :biggrin:

 

[heathbar0]

Um...My 95 got its 02 sensors replaced under warranty last year...Is this somthing different?

 

[Larry Bastanza]

Um...My 95 got its 02 sensors replaced under warranty last year...Is this somthing different?

Talk about not seeing the forest for the trees:redface:.

Up to 150K miles the car is warranteed for 02 sensor failure.

TSB: http://www.nsxprime.com/FAQ/Reference/tsb/98-031.htm

Regards,
LarryB

 

[ffffanman]

That is why this site is a group effort!
Trev