Sorry for the long post but the devil is in the details....

My G25x started throwing P0101 code (bad MAFS) at around 60K miles but turned out it was a dirty air filter. AT around 90K it came back but air filter change didn't clear it and I tried using MAF sensor cleaner on both sensors and I must have damaged the other because I got the P0101 and P0101B(i.e both sensors) I can reset but the light comes on anywhere from 1 mile to 600 miles after reset. I broke down an purchase to new sensors from RockAuto which were " HITACHI MAF0031 Sensor Only Actual OE Part " for only $84 each ( cheap compare to +200 each from infiniti ). Put them in as well as new Fram air filter ( Purolator ones I had before appear really cheaply made but worked ) Cleared the codes with 3 hour off battery and everything seems good ( more power ) except 350 miles later light came on and same codes are back. I have cleared the codes with my scanner / gas pedal stomp / and battery off but I notice I have both codes are now listed as permanent. Could not doing the Universal Trip Pattern Drive Pattern to clear the permanent codes cause the codes to reappear even if the problem is corrected?

Thanks for any ideas.
noobG25x

Did you complete the idle relearn process after replacing the MAFs?

Thanks for the response RED_DET,

Didn't know there was a idle relearning process.
Do you know it?
I just did the Universal Drive Pattern (+30 seconds idle, 10 minutes +40 mph, +30 seconds idle) but have not check with my scanner to see if the permanent code removed.

Just checked with my scanner and all codes are cleared.

Thanks again
noobG25x

It is worth giving it a shot.

http://www.nicoclub.com/archives/g35-ho ... rning.html

Most definitely, Thanks for the link.
400 miles and no SEL light yet... ( hope I don't jinx it )

This is something similar to my G37Xs (2009). one day my car started bucking and wouldnt go above 2500 rpm. NO CEL! read the codes and cleared them and it was MAF B out of spec. Cleared the codes to get home and it ran great for the week it took for my new MAF to come in. When it came in I replaced it and not a week later it happened again. Actually seems to happen every few days. Same code, MAF B. Got new air filters, and same deal.
I did not do the relearn process, do you think thats my issue? I have resigned to just clearing it once in a while but its a PITA as it has left me on the side of the road several times in bad places.

mxquattro wrote:This is something similar to my G37Xs (2009)
I did not do the relearn process, do you think thats my issue? .

Wouldn't hurt to try it

04pathse wrote:

mxquattro wrote:This is something similar to my G37Xs (2009)
I did not do the relearn process, do you think thats my issue? .

Wouldn't hurt to try it

Good point. I just did it, so Ill report back after a week or two if it doesnt happen

mxquattro wrote:This is something similar to my G37Xs (2009). one day my car started bucking and wouldnt go above 2500 rpm. NO CEL! read the codes and cleared them and it was MAF B out of spec. Cleared the codes to get home and it ran great for the week it took for my new MAF to come in. When it came in I replaced it and not a week later it happened again. Actually seems to happen every few days. Same code, MAF B. Got new air filters, and same deal.
I did not do the relearn process, do you think thats my issue? I have resigned to just clearing it once in a while but its a PITA as it has left me on the side of the road several times in bad places.

mxquattro,
Did you by Infiniti MAF senor or so called OEM parts? I am thinking I should have spent the +400 for the two Infiniti parts and not the RockAuto ones even though they appear to be the same ones I had that "failed". OH and I did jinx it because the SES (Service Engine Soon) light came on at 650 miles. I did the full Monty relearn but it came back on after 150 miles. About to call uncle and bring it to my service guy ( not Infiniti but really good ) and let him have a go at it. LAST result is dealership.

noobG25x wrote:

mxquattro wrote:This is something similar to my G37Xs (2009). one day my car started bucking and wouldnt go above 2500 rpm. NO CEL! read the codes and cleared them and it was MAF B out of spec. Cleared the codes to get home and it ran great for the week it took for my new MAF to come in. When it came in I replaced it and not a week later it happened again. Actually seems to happen every few days. Same code, MAF B. Got new air filters, and same deal.
I did not do the relearn process, do you think thats my issue? I have resigned to just clearing it once in a while but its a PITA as it has left me on the side of the road several times in bad places.

mxquattro,
Did you by Infiniti MAF senor or so called OEM parts? I am thinking I should have spent the +400 for the two Infiniti parts and not the RockAuto ones even though they appear to be the same ones I had that "failed". OH and I did jinx it because the SES (Service Engine Soon) light came on at 650 miles. I did the full Monty relearn but it came back on after 150 miles. About to call uncle and bring it to my service guy ( not Infiniti but really good ) and let him have a go at it. LAST result is dealership.

I did, I got the exact same one as you did from Rock auto. I did the full relearn procedure and this weekend it did it again Killing me! Im thinking maybe I just need to pull the battery terminal off for a while and then try again, I think that relearns the ECU too. I brought it to the dealer and they say it could be 'several hours' of troubleshooting, and may find nothing. That equates to about $350 which may come up with nothing. Funny thing is, I NEVER get a CEL or service engine soon light. nothing. No lights at all. I just cant go over 2500rpm.

Im literally ready to sell the car over it.

Please keep me informed on what you find!

mxquattro wrote:

noobG25x wrote:

mxquattro,
Did you by Infiniti MAF senor or so called OEM parts? I am thinking I should have spent the +400 for the two Infiniti parts and not the RockAuto ones even though they appear to be the same ones I had that "failed". OH and I did jinx it because the SES (Service Engine Soon) light came on at 650 miles. I did the full Monty relearn but it came back on after 150 miles. About to call uncle and bring it to my service guy ( not Infiniti but really good ) and let him have a go at it. LAST result is dealership.

I did, I got the exact same one as you did from Rock auto. I did the full relearn procedure and this weekend it did it again Killing me! Im thinking maybe I just need to pull the battery terminal off for a while and then try again, I think that relearns the ECU too. I brought it to the dealer and they say it could be 'several hours' of troubleshooting, and may find nothing. That equates to about $350 which may come up with nothing. Funny thing is, I NEVER get a CEL or service engine soon light. nothing. No lights at all. I just cant go over 2500rpm.

Im literally ready to sell the car over it.

Please keep me informed on what you find!

mxquattro,
I just "helped" my son buy a used 2010 Altima 2.5S and seemed fined when we test drove it but on the way back to his home ( 3 hours away ) he found out he got one with the "limp mode" issue.
On long drives the speed he could push it would go down over time i.e. 2 hour only 65 mph, 2.5 hours 60 mph, 3 hours 55 mph.... Could you have this type of problem. His was covered by extend warranty by Nissan so they replace some switch on the tranny. ( he really didn't give me details but they had to have the car for the day and they mess up the exhaust so he had to by a new cat....)

I dont think that is my issue. Mine goes along just fine, then a few seconds before it happens the throttle response goes flat, them BAM, limp home mode. Again, no lights whatsoever on the dash. The code it brings up is MAF B bank. I clear it and continue for another week or month or however long.

I did notice that it will only happen after 20-30 minutes of light throttle driving. If I can go WOT once in a while or at least a heavy foot, its fine. Its always after about 20 minutes of side road, light throttle driving.

Still have the P0101, P0101B... So going to try cleaning the Throttle body (Just over 100K miles and never cleaned so they needed cleaning)
Trying not to move the butterfly valve when I spray and clean with toothbrush. Wish me luck

They need cleaning? Huh. I have 200K+ on mine and never did that, I guess I can try it. I think when it gets warm here (hopefully that day will actually arrive) I can try that. It happened again to me this weekend and I knew it was going to happen. was at about 2000rpm and throttle response went totally flat. I floored it and nothing happened. No downshift, no nothing, just stayed flat and at 2000rpm. then it started to buck and fart. Still no CEL. Clear the code and move on again. GRRRRR Keep me posted on what you do and how it goes.
AND GOOD LUCK!

SUCCESS! (I think)

I check this video before tearing into my throttle bodies.

(Pat Goss from Motorweek)

I did not open the throttle plate just scrub around it and did not push it open. I left them plugged into power while cleaning.

When I looked at my throttle bodies they were completely blocked (no light around the throttle plate) Took a BRASS brush (soft metal) and throttle body cleaner to them as a first pass(could see light around the throttle plate now) IF it worked, I was going to get back into them for a final pass. Its been 1100 miles no SES light and all permanent codes are cleared.

So I went back into it today and gave them another cleaning. Took some pictures but could not figure out how to upload (let me know if you are interested in seeing them). They just show the light coming around the throttle plate now.

But bottom line is the code P0101 and P0101B were caused not by the MAF sensor but dirty throttle body.

Anyone want some used MAF sensors? only 100K miles on them....

noobG25x

Holy crap. Im going to give this a try. If this works Im buying the beer. Its starting to get warm here now so Ill definitely tear into it maybe this weekend. Fantastic!!! I have over 200K on my car so Im afraid to see what they look like! Ill definitely keep you posted

Good luck mxquattro,

I spent a lot of time looking at different youtube videos on people cleaning throttle bodies (G35 and G37's) just be careful and don't push the throttle plate if you can avoid it.
(or use the trick Pat Goss had on the video)

My symptoms sound similar, except that I do get the SES light coming on eventually. I learned how to get the light to turn off. When I did that the car soared past 2500RPM with no problems. The light came back on. I reset it again after putting in new air filters. I haven't drive much since then. My question is for those who had the SES light come on. Did you try resetting the light, and if so, what was the result?

davidcosmejr wrote:My symptoms sound similar, except that I do get the SES light coming on eventually. I learned how to get the light to turn off. When I did that the car soared past 2500RPM with no problems. The light came back on. I reset it again after putting in new air filters. I haven't drive much since then. My question is for those who had the SES light come on. Did you try resetting the light, and if so, what was the result?

Did you pull the codes from the flashing SES?

http://www.brianhaddock.com/2010/readin ... san-altima
I think its list here too but this is the one I have bookmarked.
works for my infiniti G25x....

My SES came back on after reset anywhere between just starting it and 650 miles driven (@2500 and no light so far )

Good luck

I just ordered a ODBII reader so I can get the code. It should come in a couple of days. I'll check in after I get it. I reset the SES light yesterday after changing the air filters. I drove twice for a total of around 20 miles before the SES light came on again and it sputtered at around 2500 rpm. I hope this is not a rabbit hole I end up throwing money down into! Thanks for checking in and adding to this thread.

I got the sensor yesterday. Pulled the code. There were 2: P0021 and P0524. I called the dealership to drop off the car tonight. I'm afraid I'm in for a HUGE repair bill. I just bought this car about 2 weeks ago from an Infiniti dealership! Unfortunately, it was As Is. Ugh! Any suggestions?

davidcosmejr wrote:I got the sensor yesterday. Pulled the code. There were 2: P0021 and P0524. I called the dealership to drop off the car tonight. I'm afraid I'm in for a HUGE repair bill. I just bought this car about 2 weeks ago from an Infiniti dealership! Unfortunately, it was As Is. Ugh! Any suggestions?

Read this

https://www.myg37.com/forums/engine-dri ... p0524.html

Thanks! I have read through that thread. Unfortunately I think I'm heading down the same road. Got the car after they cleared some debris from the selenoid. The thought was that this might be causing the issue. Drove it about 30 miles before it came on again. Need to drop it off again tomorrow morning. So far, $250. I was told that the next step is in the $1K range. From what I read, I'll be fortunate if that's all it costs me.