BennysMAXIMA

Just got my codes pulled and got a P0171. Any of you all seen this before and what the most likely fix. In the morning it idles rough for abot 1 minute then the RPMs increase slightly and all is well.

I'm leaning toward the MAF. But, a few weeks back I check my throttle body for debris and gunk. I don't recall if it appeared soon after thou. I should probably check to verify all is tight.

Any ideas guys?

IceY2K1

iTrader: (3)

Possible Causes:
- Intake air leaks(doubt it since both banks would be lean)
- Heated oxygen sensor 1 (front)(doubt it since you'd have other codes)
- Injectors(my bet)
- Exhaust gas leaks(maybe)
- Incorrect fuel pressure(maybe)
- Lack of fuel(maybe)
- Mass air flow sensor(doubt it would act normal)

My bet is a bad injector on the firewall side. The dealer can easily test each injector with a Consult, since getting to firewall side injectors is going to be a PITA. *IF* you figure out a way, try using a multimeter to measure if the resistance is between 13.5-17.5ohms. Also, try putting your hand on each injector as the car is first stumbling when started and see if you can feel one not clicking, might not be possible with intake manifold on though.

Last, injectors don't typically go "bad", they just get clogged. You can *TRY* using BGK fuel cleaner and see if you can knock the crap loose. The best option would be to have a complete MotorVac cleaning or at least pull the injectors and send them in to PTR, http://www.ptrsds.com/injectservice.html, for cleaning and flow analysis.

Raven

Hey man, you're in luck, I had this same problem em.

See this thread:
http://forums.maxima.org/showthread.php?t=302224

Basically, I had to replace the MAF and the issue (we later found out) was from overoiling my high flow intake. The solution is a $100 one if you do it yourself and follow the thread above. The dealer will easily put you over $600. I'm not a car buff either and it was an easy install.

I hope this helps.

Raven

here are some good instructions:
http://forums.maxima.org/showthread.php?t=339372

best of luck

dannodotcom

Same thing happened to me at the beginning of a 5000 mile trip, at first didn't trigger code but would run rough on startup for about 30 secs then all was fine. But by the end of the trip it was not running very well, power fluctuating on the highway, driving through mountains pulling a trailer was getting scarey. Bought a codereader on the trip as the SES light came on and pulled code P0171. Made it home, and shortly thereafter almost didn't make it home from work, press gas pedal down and nothing would happen, limped home and it's been my garage ever since. I've been driving my old truck to work. I've concluded that it's got to be the MAF and have ordered a new one from Dave Burnett at Southpoint Nissan in Austin TX. Dave seems very knowledgable and agrees that it is probably the MAF and also says it is about the least expensive part to replace for this problem. Cost $85 plus shipping and is an easy part to replace. One thing you might want to try is to disconnect the MAF and see if the engine runs, the ECU is programmed to run the engine rich up to a max of 2500 RPM in the event of a total MAF failure. I did this and the engine ran ok up to 2500 RPM and idled smoothly, which it would likely not do if the injectors or the fuel pump were the problem. Connected the MAF back up and the engine would not even start! When I get the new MAF installed I'll let you all know if it worked.

Cheers,
Dannodotcom

allenmason

Rough initial idle with a cold engine plus SES code 171 (or 174) = bad MAF

Its been a common problem reported on the board over the past two years.

Why does this happen? Outside of the general MAF displeasure many members have posted, an good number of MAF problems are caused by "stuff" getting by the filter. Some aftermarket air filters have fitment problems and allow a small amount of debris to flow around the seal bypassing the filter material and (over)oiled filters (K&N, et al) may release small droplets under high volume conditions that impact/deposit onto the MAF. The MAF we use is a hot filament type mounted on a thin piece of plastic suspended in the airflow past the filter. I had the same problem as you are experiencing after running F*** air filters for 50K miles. When I replaced the MAF, I checked inside of the air tube between the MAF and throttle body and found a thin coating of dust lining the tube and falso ound a line of dirt aound the air filter seal indicating air leakage past the filter. Hence I now use only Nissan stock air filters.

dannodotcom

Allenmason, I have to disagree with your assessment of the problem with the MAF. I realize that you are a retired engineer and probably very wise, but in my case the MAF is absolutely pristine and spotless, not a bit of dirt/dust on it and yet it doesn't work worth a damn. There was no leak past the air filter. I think something electronic inside the unit has failed. I intend to take it apart after I get my replacement unit next week, and will see if I can determine what has failed. Being a smart engineer, maybe you can also shed light on why the coils fail after about 50,000 miles?

Cheers,
Dannodotcom

spirilis

iTrader: (2)

My coworker's 2000 automatic GXE exhibits this now. I pulled his codes after lunch today and it was P0171. His Long Term Fuel Trim values were pretty high too, something like 23% for bank 1 and 33% for bank 2. Makes me wonder if it's either MAF or fuel problems. I told him to take it to the dealer regardless... (he's not into DIY stuff and I don't have time to help him fix it)

allenmason

Dannodotcom,
My MAF, too, was clean - the air tube connecting the MAF assembly to the throttle body had a noticable dust-like coating, hence the supposition for my particular MAF failure. Regardless of the reason for failure (and Nissan quality comes up often), I believe you are joining the ranks of 5th Gen Max owners who have experienced MAF issues.

As for the early production 2K coil failures (you had to ask an engineer!) -- The 2K Max had all new engine and transmission electronics (and much more) that production year. Hence, Nissan (and their customers) experienced several quality/design issues on the 2K Maxs, espicially the early production models. Problems like:

-Early production coils that fail early, as you stated -- a pure quality issue
-Early production automatic transmission solenoids and electronics not designed for enthusiastic drivers.
- Emission data variables intially set too tight in the ECU software that would trigger a P0420 code at about 40K-50k miles.

The 5th Gen TSB list is more exhaustive. All auto makers have similar lists of minor and major issues for their products, but I had not expected to experience problems like those I've stated on my beloved Max.

5thGENJORDAN

I just figured id throw this out there for anyone having this problem, I apologize if im posting something thats on here somewhere else. but i was getting the p0171 code, so the first thing i tried before spending tons of money on 02 sensors and maf's I ran seafoam in the gas tank and in the throttle body and used some throttle body and maf cleaner, and it cleared everything out beautifully,of course it smokes alot but that lets you know its working. cars no longer lean and it cleared my service engine light. so seafoam is the cheapest thing to try first.

Professor

iTrader: (4)

Had some problem for months, no other codes, turned out to be the MAF, i would always have pinging on hills even with 93 octane, cleaned maf 400 times to no avail, bought a new one, codes went away and engine no longer pings. i had both lean codes.

MAXIMUS86

iTrader: (10)

Hi guys,
I haven't been on here forever lol but have owned my 03 Maxima since almost new and used to be on this Forum almost every day when I was a teenager (bought the car when I was 18) now into my 30s and still love my maxima. she has 175k miles and this is the first time it broke on me, of course I take care of her but now idk what to do. I got the rough startup and idle out of no where a week ago with p0171...since the car has high miles I decided to spend some money on new parts. I got new injectors, coils, spark plus (they only had 20k miles on them but I decided to change them anyways) and a new MAF sensor as well as 02 sensor.
I replaced them all hoping the issue goes away but started it and still runs like crap. I haven't driven it since the first day it threw the code. anyone else knows what else it could be? The only other code it was throwing was for a faulty fuel level sensor which broke 4 years ago. I did replace that part as well yesterday. Now the only code it throws is the fuel level sensor, but it misfires and runs really rough. Im not sure why the fuel level sensor code if back since the part is new. any ideas?
I disconnected my MAF wile it was running and it ran worst so I know that part is working. theres no sign of furl leak, or air leak.

mclasser

Check the air intake tubing for cracks and loose clamps. Cracks can be hard to spot on the car so remove the ductwork and carefully look b/w the folds. Your vacuum lines are likely rotted by now so inspect those as well.

MAXIMUS86

iTrader: (10)

I have an aftermarket aluminum intake but I checked all the rubber joints and they were in a good shape. I recently had to replace some coolant hoses because they were cracked. I live in AZ so its understadeable. Ill try spraying brake cleaner around the intake and MAF area to see the change in atmosphere changes the way the car runs. Maybe I can pinpoint a leak. Im hoping it is a leak because I don't know what else to do. The new check engine was only for the fuel level sensor even tho the car ran like crap. I started it twice and each time it ran for 10 seconds or so. first time it almost died, but it didn't throw any specific codes. Ill try and run it again after work to see if I get the same code or something new.