Mine was brand-new in a OEM Nissan box with the manufacture date on the box itself. I also had "E0003" etched onto the MAF itself, and the old one had "E0000", so I'm assuming I was on the 4th revision of the MAF design.

 

I recommend Dave Burnett (parts manager at a Nissan dealership) that cuts big breaks for Org'ers like yourself. He's known as "Dave B" on the forums and you can reach him by calling: 1-888-254-6060. It'll probably run you about $80-90 shipped. Call your local Nissan dealership for a comparison - you won't be disappointed.

I purchased mine off eBay because finding Dave's phone number proved to be a bear (with the oldthread links embedded in the FAQ). The seller's ID is dealzoneverything, but I checked and he does not have a MAF listed.

 

Yeah, I'm just saying that I don't think it would take 45 minutes to update an ECU. And since my dealer quoted me a 30 minutes, it must take even less to do.

 

Worked fine for me. I just tried it again. Make sure you select Mazda in the drop-down by the part number.

www.mazda-parts-dealer.com

 

will the P0420 (Catalyst System Efficiency Below Threshold (Bank 1)) code effect gas mileage?

First full tank of gas since my ses light came on due p0420 code and I got 290 to the tank, all city mileage.

I have not owned the car long (3 tanks worth of gas) but it seems quite low. Related?

 

Ok today i bought the CNC MAF air cleaner and did the procedure and reset my ECU. After couple of miles driving the SES came back on, went to local autostore to check and it throw P0171 again. Is this a possible bad MAF or i need my injectors to be cleaned or i need a tune up? pls help me.........

 

I think that code is thrown if the rear O2 sensors detect too much unburnt fuel getting past to the catalytic converter. This could be due to errant front sensors that inform the ECU if it needs to throw more gas into the chamber (which ties that information into the readings from the MAF). Running rich uses more fuel without it being necessary.

I'd borrow an OBD-II scanner and check your MAF reading to see if it makes sense to the spec first. If that looks good, I'd start looking into my O2 sensors.

*shrug*

 

For me it was the MAF. For many Org'ers it was the MAF. OBD-II scanner will show you what the ECU is reading from the MAF and how far off it is. The actual spec you will need the FSM or somesuch.

 

got a link for the maf specs? I don't have a FSM.

I'm searching now.

 

From the 2001 Maxima FSM:

Voltages:
ignition on, engine off, 1.0V
idle, engine warmed up, 1.2-1.8V
2,500 rpm, engine warmed up, 1.6-2.2V
Idle to 4,000 rpm, 1.2-1.8 to 4.0V (should be approx linear increase to 4,000 rpm)

Readings:
Idle, 2.0 - 6.0 g·m/s
2,500 rpm, 7.0-20.0 gm/s

I just replaced my MAF and before my MAF readings were 2.9 gm/s at idle and 8.1 gm/s at 2,500 rpm. I haven't checked the values since the replacement.

You should get a copy of the FSM, it's not too hard to find and it's a good reference/learning tool.

 

FSM: http://www.vq35de.com/ESM/


No, this code should in no way affect fuel consumption,this code is thrown when the computer detects a increase in the ratio of front and rear
heated oxygen sensors switching frequency
..... oxygen sensors put out around 1v in rich conditions and closer to 0v in lean. The computer adjusts fuel injection pulse duration to achieve an ideal air fuel ratio by using the signal from the front O2 sensor during closed loop controll = a reduction in fuel volume if the mixture ratio is rich, and an increase in fuel volume if it is lean.

So during normal engine operation continuous adjustment of short term fuel trim makes the front O2 sensors output switch back and forth between 0 and 1v. The computer monitors the switching freqency of the front o2 sensor and compares it to the switching frequency of the rear 02 sensor, the rear O2 sensor is behind the precats, and has a longer switching frequency due to the precats oxygen storage capacity.

( rear O2 freq) / ( frontO2 freq)= ratio used by computer measures efficiency of 3 way catalyst in precat

As the precats degrade, rear O2 switching frequency increases and the above ratio increases, when it gets above a preset limit (.75) you get p0420 CEL. In order for this CEL to appear both front and rear O2 sensors must be in good working order, malfunctioning O2 sensors will trip other CELs but not this one. ....So does a P0420 mean you have a bad precat, not necessarily, many manufactures including Nissan set the efficiency limits a little to strict and as the precats and O2 sensors and engine components age, it become difficult to stay within the limits, even though the individual components are not broken...hence updating the CPU. Which works sometimes, but plenty of people need a new O2 sensor and precat to eliminate the CEL.

So unless you are still under warranted, a $40 O2 sensor simulator is the way to go, install it and forget it

 

Thanks, I'm def going to get one soon

 

Curious as to what you’re using to get that reading?

 

AutoZone is the last place to buy car parts, IMO. 3 starters in a row for my old Accord and all three would grind on about every 3rd or 4th start. Finally went to an all Honda wrecking yard, put in a used starter and it worked perfectly. Had to show them my receipt for the junkyard starter to get a refund for their starter. Use to have problems with the master/slave cylinders I got from them when I had a 5 speed Celica. Just don't trust their parts anymore.

 

That was just from the 2001 FSM, page EC-155. The actual values I got for my car, pre MAF replacement I got from a friends OBD-II cable + laptop.

 

gm/s = Coolness.

 

I just got P0134 code relating on front B1 oxygen sensor, and I changed MAF sensor. It works...., I feel like needing to reprogram. I bought Oxygen sensor for front Bank 1 area as well just in case, and I don't need this any more. The retail price is 140, but I bought this with $108 at the Mazda parts..., in which someone intoroduced here. If somebody need this, I can sell it $100, negotiable, including shipping. It is genuine part, and good for 2000 and 2001 model with federal emission. sung.91@osu.edu. Thanks for every thread helping me figure out this problem.

 

After exploring the forums, and this thread in particular, I initially figured my symptoms (stalling, sluggish accel, etc.) and P0171 code indicated that I need a new MAF and an ECM reprogram. However, I am also pulling a P0134 code (HO2S Circuit Insufficient Activity Bank 1 Sensor 1) which seems to indicate my HOS1-B1 sensor is bad. I see that the previous poster also threw a P0134 code which a new MAF fixed. Is it more likely that a bad MAF is causing both codes, that a bad O2 sensor is causing both codes, or that both the MAF and O2 sensors are bad?

 

I read through this thread and know now that test results can lie and that it could be MAF although I only get the fault code for one bank.
Smog Test Result:
Visual Inspection: Pass, Functional Check: Fail because of the one and only fault code P0171; Emissions test: pass
I wonder if the following results from the smog test has relevance for the diagnosis:
PCV: Pass
Spark Control: Pass
Wiring to Sensor: Pass
Liquid Fuel Leak: Pass
Fuel Evaporative Controls: Pass
Fuel Injection: Pass
Vacuum lines sensors/switches: Pass
Fuel Cap Integrity Test: Pass
Ignition Timing: n/a
Catalytic Converter: Pass
Oxygen Sensor: Pass
Other emiss. related components: Pass
Fuel Cap Visual: Pass
Fuel EVAP test: Pass

I do not experience any problems while driving - maybe an ever to slightly acceleration reduction. I have one big benefit, though - after guzzling fuel like crazy my max now uses the expected amount of fuel - like 19 miles per gallon on the high way before it was 14 miles per gallon or less miles.

Some month before the Smog Test a mechanic diagnosed the Check Engine Soon light for $90 and said that the oxygen sensors need to be replaced (because they need to be replaced every 30,000 miles and mine has 110,000 miles without ever changing the O2 sensors according to him - I bought the car with 92,000 miles).
He wants to change all of the O2 sensors and offered to do that $1,000. I did not have the money to do it. He switched the light off, within 10 days it was on again, after a while it was off and then on again but now it is continuously on.


It drives me crazy that I don't get the Smog Certification although I do not contribute to the pollution with the car - au contraire. And that I should change something although the car stopped guzzling fuel.

Is changing the MAF and reprogramming ECU the cure for all and the first diagnosis of the mechanic bull ****? Or can I assume that when I paid $90 for the diagnosis of the check engine light that he actually measured the function of the O2 sensors - or did he just get the same fault code as the smog test and picked one possible reason?

 

if you have a bad maf, does that make your engine clatter/tick/rattle when you step on the gas pedal?

b/c i have the 0171 code, and when i accelerate uphill or on a highway ramp, i feel like the car's power is not as strong as a 6-cylinder should be. And i use octane 93 gas.

 

Either clean or replace your MAF. There is a *LOT* of information on this in the forum. Make sure you use MAF cleaner only. If that does not fix it, get a new MAF sensor. I am assuming you have 2000 or 2001 car and a new sensor should be about $100. You will need security torx bit to remove the old one (whole set costs $10 at NAPA). You also need extremely strong thumb to take the connector off the old one.

- Vikas

 

Greetings everyone,
I just came across this rather old forum post after doing a search on the P0171 code. My mother-in-law has a 2000 Maxima GXE that just threw that code this weekend. The car only has 68K miles on it, but she lives in an area that gets a LOT of dirt and dust. The first thing I checked was the air filter, since my wife's car once threw the same "Fuel System Too Lean" code due to an airbox that didn't seal well. I noticed that part of the rubber seal around the filter seemed to be a bit deformed, possibly from when I had the oil changed a couple of weeks ago and the oil change people pulled the filter out to check it (maybe they bongled it up a bit when putting it back -- I had a hard time getting it out). I'm going to replace the filter and reset the light, then use her car for a couple of days to see if the light comes back on.

I saw a lot of replies in this thread pointing to replacing the MAF sensor. There were some other threads here as well. Several folks said they replaced their MAF sensor without needing an ECU reflash. I'm skilled enough that I could replace the MAF, but obviously, I can't do an ECU reflash. I checked with a local dealer, just for the heck of it, and they quoted me between $380 and $780 for a MAF. WTF??? They said it had to do with whether a "reman" was available from Nissan. Oooooo kay...

Is there still someone around here named Dave B? I understand he is somehow affiliated with either Nissan, or a dealer, and he has sold MAFs to people here for around $80. Am I reading that correctly? If so, how would I go about obtaining one? It seems like a relatively inexpensive way to rule out a problem.

And of course, if anyone has other advice, it will be gladly accepted!

Thanks!

 

Oh, I almost forgot, one other thing, too: I've read write-ups on how to replace O2 sensors. It seems easy enough, but living in a condo with a 1-car garage, I have no place to work on a vehicle, nor do I have a jack or any other way to raise the car up (a lift would be nice, eh?). Is there anyone in the San Diego County area that would be willing to assist me?

Thanks!

 

go to www.partsgeek.com

http://www.partsgeek.com/catalog/200...ss_sensor.html

you have a choice.

OES, is the original "new" oem part. will need to take car to dealer to reflash. tell them you just installed the "updated" maf sensor. show them the notice from inside the box saying a reflash may be required.

It should be $100 or so. Not $700+ the quoted. They gave you a quote of the "original part number" replacement plus labor... A new originial part number replacement would cost over 400.

or you can get the Cardone reman... for less.. and no reflash as it's remanufactured to the original's specs. The Updated one was produced to work on several Nissan cars/trucks. That's why you may need to reflash the computer for the updated maf to work with your car by "VIN".

And the car may drive perfectly fine except you won't be getting all the "performance" out of the engine with an "unmatched program" to that maf sensor.

 

Thanks for the response! I checked the site out, and that seems a LOT more reasonable. From what you're saying, if I'm understanding correctly, there doesn't seem to be any reason to go with the OES part. If the reman is cheaper (after you get the core refund, that is), AND does not require a trip to the dealer for an ECU reflash, then is there any reason not to go that route?

If I were to go with the OES, though, I'm concerned that if I called up the dealer and said "I need an ECU reflash", that they would only do it if there was some specific problem with the car. I've run into similar dealer stubbornness before, and wondered if that could be a problem. Dependent on the dealer, perhaps?

Thanks again!

 

personal preference.

I replaced mine before I heard about partsgeek. Although there are many online dealer sites that sell the Niisan oem updated maf for around that price... nissanpart4u.com is another one.

Ultimately it's up to you. the Reman part does not say you have to reflash or anything so I can only assume it's reman as in small resistors/capacitors replaced in the sensor unit that matches the original part that came on the 2000s...

Like I said the updated one was to replace the numerous maf issues on multiple Nissan cars.

You can always call that dealer or another Nissan dealer first and say you replaced the maf with the updated maf part and you need to computer reflashed to match the maf... blah blah and how much is that... so one. They should know what you're talking about.

If not then try another dealer.

 

Thanks for the advice! I'm going to go ahead and order the OES product from partsgeek.com. I talked to a local dealer's service department, and the service guy was very knowledgeable about Nissan TSBs and didn't give me any difficulties. He said I can bring the car in for an ECU reflash after replacing the MAF and the air filter, and it would cost about $100. I'm also going to replace the Idle Air Control Valve, since this car has been experiencing the stalling/near-stalling problem at warm startup that a lot of other people have discussed.

He also mentioned that some of these cars have had problems with A/C coils leaking onto the ECU and damaging them. (Whose idea was it to put a computer under a source of water, anyway??) They'll check that for me as well.

Now, off to find an IACV thread (I'm sure there is one) and post some questions there!

 

2001 nissan maxima SE M/T 5spd. NEVER got a troubleshoot code until i plugged it in after a rough night of driving, it came up as a too lean bank 1, or p0171.
I was driving in a real heavy rainstorm, and i mean torrential. as soon as i hit dry pavement i down shifted from 5th to 4th and hit the gas to bring it up to round 70, as soon as i downshifted i lost engine power (hammered the gas and it completely stripped the power) downshifted to 3rd and then it stalled, but it started right back up and drove home no problem. next day it was idling at about 500rpm when i started it but would NOT stall, BUT after driving it all day it started literally catching itself right before a stall (300-400rpm) and it actually stalled once or twice. i threw it in neutral i added 'heet' water remover incase rain got in my cold air intake (injen), then cleaned my MAF sensor with brake cleaner and a qtip...now it still throws NO codes but the 'snap-on diagnostic tool' claims it's running lean..BUT the rpm level is acting funny, it stays at 1,000rpm til it comes to a complete stop now (while in neutral) and there is a loud 'ticking' sound..sounds like the engine leveler which always kinda clicked BUT NOT nearly this hard since the issue all arose.


MAF reads perfect, so does Idle/air volume is fine....only evidence is o2 sensors (Sensor2 Bank1; Sensor2 Bank2) do not respond at all (steady line at .24 & .30, respectively) until however i hit the gas..then they are fine. my car also cuts the throttle when trying to stay steady at 2,000 rpm [sorry for all the info!!] and i appreciate any help ladies&gents.

 

Quoting myself... LOL. Anyway, I just posted an update on one of the IACV threads, but thought I'd post here as well. I ordered an IACV and MAF sensor from Dave B. They arrived last week and I took the car in to a local Nissan dealership this morning to have them installed. The service rep came in earlier and told me that they tested the IACV and it was working perfectly, and that the MAF was the cause of the problems. They're replacing it, and then they'll do the required ECM update and idle re-learn. I'm also having them clean the throttle body and fuel injection. Once that's all done, I'm going to drive it as much as possible over the next couple of days and see how it does, and assuming that the IACV doesn't need to be replaced, Dave B. said I can return it.