Sorry for the late update, I have since replaced all four 02 sensors with Denso OEM replacements. Now since the replacement the two upper stream 02 sensors are good but, the lower stream 02 sensors are still throwing a code. I have replaced the lower stream twice, both time using new 02 sensors. The shop that read the codes have a real time datalogging scanner and they told me that the 02 sensors were turning on and off. If anyone has had this problem feel free to give your 2 cents. thanks

 

In my 2K Maxima, I ran it with a CEL on for nearly 2 years, because it was throwing O2 sensor codes, and one of the supposed fixes was to replace the pre-cats at a cost of $300-$400 each. I never did replace the pre-cats, and I also never did replace the O2 sensor(s). What I DID was clean the MAFS very well with CRC MAFS Cleaner (remove it and unplug it from the car, and let it dry thoroughly before attempting to reinstall and start the car.) This pretty much cured my driveability problems, and it increased my gas mileage. After I put it back together, I took it down to Advance Auto Parts and had them scan and clear the codes. I drove it normally after that for about another 1000 miles before I sold the car. During that time, the CEL stayed off, and no codes reappeared.

Cliff's Notes: CLEAN YOUR MAFS!!!!!!!!

 

Damn still have the two lower o2 sensors bad, HELP

 

I just cleaned the MAF with CRS and still have the same problem.

 

i had the same problem in my G all 4 02 sensors went bad... both up stream and down stream... the car was running lean... turned out to be a vacuum leak, all 4 02 sensors were fine

it may not be the 02 sensors at all, could be an exhaust leak, bad cat ect...

 

A bit more infomation for you guys... while my car is beinging scanned the bad o2 sensors turn on and off then the two o2 sensor turns off completely. Maybe a wire issue?

 

Good info... where did you find your vacuum leak? I hope its not my cats. anywhere from $300-$400 a piece!

 

my problem was up stream, before the cats so im not really sure what your problem could be.


check out

http://www.alldatadiy.com/

you have to pay but the info is great

 

Are all 4 O2 sensors the same on our cars?

 

did you have it checked for a vacuum leak. For all 4 do go out is rare .. but the swap cured the 2 b4 da cat.. Take it to Infiniti.. $134 to check it out. Hows your gas mileage now?

 

Check your grounds there are some ecu grounds that may throw a code for 02 and still allow the car to have no other issues also one of the fuze links on ur batttery pos. clamp supply power to all the 02 sensors check that. (i work as a nissan tech) and 90% of mechanics dont know what they are doing so they see a 02 sensor code they just replace that but dont forget the wires and ECU can also be faulty so can an exhaust leak before the cats, bad fuel intake leak (most the time would have lean code if this was case) it goes on...... Seeing how all 4 threw a code i dont think exhuast is issue. Pull one out see if its dirty (clean with carb cleaner if necessary)

 

Clean your throttle body 2...

 

I had 1 o2 sensor and 1 a/f sensor bank 1 code keep poping up radomly. Dealer changed both sensors 2x, then they claimed a hair line crack in the cat so replaced that..... Then finally they gave me an ecu...... Witch cured the problem.

 

Ok well now I'm having the same issue. My codes are P0031 Heated Oxygen Sensor Heater Bank 1 Sensor 1 Low , P0051 Heated Oxygen Sensor Heater Bank 2 Sensor 1 Low , P0037 Heated Oxygen Sensor Heater Bank 1 Sensor 2 Low, P0057 Heated Oxygen Sensor Heater Bank 2 Sensor 2 Low

They are all the same problem....WTH???

 

Dolly, what were you able to find out? Or anyone? I have a 2004 Infinity G35 and the same thing happened. All 4 o2 sensors showed up. I replaced them and cleared the code, but within shutting the vehicle off and on a few times, the SES came back on. I've heard everything from clearing the code, then running it any where between 50-150 miles(cycle) until the computer learns it has the new part. I haven't tried, but heard to check the fuse too? Any help....