Just tested my O2 sensors... the front two are bad and the rear one is slow but acceptable... probably cuz the rear is on the second one already...

Nissan bought some cheap quality sensors!

Oh well... hopefully my mileage should go from my present 18mpg back to my 23 for all around driving... Gas is still pretty expensive...

 

On what basis did you reach this conclusion?

 

Says the $2500 OBD scanner... both are reporting in rich

 

Thank you for the clarification. The scanner tool says the Oxygen Sensors are sending a "rich mixture" signal. You decided the reason was "Nissan bought some cheap quality sensors!" Perhaps you have jumped to a wrong conclusion.

1) Maybe the sensors are still good, and are telling the truth. Maybe a defect elsewhere in your engine is causing an over-rich mixture. This could be the result of
- a bad Engine Coolant Temperature Sensor
- a bad Fuel Pressure Regulator
- an obstructed fuel return line
- sticking fuel injectors

2) Maybe the sensors are bad because they have been "poisoned" by exposure to various substances including leaded fuels, anti-freeze, anti-seize, RTV sealants, and the residue of burned engine oil.

Your "bad" Oxygen Sensors may be delivering a message about a problem elsewhere in the engine. Those sensors may be innocent victims in this crime story. If you fail to look beyond the immediate problem and identify the root cause, you may just ruin two more sensors.

 

There weren't any other problems showned by the scanning tool... plus the tool also shows the speed at which these O2 sensors read... which indicated very slow on one and slow on the other... (relative terms obviously) the rear one is starting to slow down too but acceptable...

My engine has only about 36K on it and not burning any oil, loosing any coolant... I run 92 octane (not a guarantee granted) PLUS all the problems NISSAN has with their 95-96 sensors...

And my friend is a certified LEXUS mechanic.... I'm going with the odds here...hehe

 

It is a great mistake to believe that "No Code = No Problem". If your friend is a sharp technician he knows that the Engine Control Module does not test for ...
- a bad Engine Coolant Temperature Sensor (except for short or open circuit)
- a bad Fuel Pressure Regulator
- an obstructed fuel return line
- sticking fuel injectors

Therefore you could have any (or all) of these problems and not have any Diagnostic Trouble Codes.

I accept the fact that your Oxygen Sensors are not doing a good job. My point is you should seek to understand why, rather than grumble about "cheap quality sensors". If your criticism of Nissan was well-founded we would have many other owners complaining of failed sensors at 36K miles, and that isn't happening.

You can trash Nissan's reputation all you like. I'm trying to get you to understand that you might be overlooking something important, and if you insist on doing this it will cost more in the long run. It's your car and it's your money.

 

Daniel... I hope you didn't take my post as a slap in the face... wasn't meant that way...

But, I'm not about to remove/flow/replace my injectors... It's not worth my TIME OR MONEY...

I'll try to check my regulator...

I'll get a reading on the OBD scanner as to my engine temp...

It just makes more sense to replace the O2s right now...

I can check the computer again AFTER I replace what is "Known to be bad" at this point... If the FPR or FI are bad then it will probably read rich again...

 

I'm not offended. I said my piece on the subject. It will be instructive for all of us to see if your next set of Oxygen Sensors lasts longer than 36K miles.

 

Nissan will pay to have the o2 sensors replaced for a certain period over the standard emissions warranty won't they?

Monil

 

Luckily, my 99 SE-L is still under warranty. The service engine light came on each time a sensor went bad. Nissan says that there are three sensors in the car. The first was replace at 5,000 miles, the second last week at 28,000. I asked if they just wanted to replace the third one now just to keep me from coming back. Good Luck. Stefnee

 

hey chunger let us know what results you have with replacing the o2 sensors,i'm sure the info could help us all down the road.

 

Will keep you guys posted... I've asked my friend NOT to get me Nissan O2 sensors... I've just heard too many bad things about them...

I had a 86.5 Supra with over 150K that didn't require an O2 replacement... i think Nissan should last at least half that... that's not too much to ask, is it?

But as Daniel pointed out, it may be something else... Which really WOULDN'T make me any happier...

 

A new set of plugs and fuel injector cleaner (not sure which one did it) got rid of a "air intake temp sensor" and a "front heated 02 sensor" light. No problems for about 8 months. BTW my 85 Celica got 220,000 before I had a 02 light. I know what you mean about these parts needing to last longer.

 

I pour in a bottle of Techron once in a while...
I was hoping to have the plugs changed at 60K but maybe all the more reason to be my Iridium plugs now

Thanks Dave

 

I beleive the rear one is suppose to be slow. The rear is to test the catalytic convertors effeciency to store oxygen not the air fuel mixture. I think the slower the signal equals the better the cat is working.

 

I'm not sure on this but I thought the "reading" is in either Voltage or Resistance on the sensors (i'm sure one relates to the other) and not the 'sampling' interval... but i may be wrong here...

 

The reading is in volts. Low voltage is giving a lean signal to the pcm, and a high voltage is giving a rich signal. If your sensor is always giving a rich signal, I assume your friend pulled a vacuum hose to create a lean condition to test how quick it would respond. The front two should reacte quickly and the rear should have a delay.