PO171 / PO174 - How Do I Fix This?
#1
PO171 / PO174 - How Do I Fix This?
A few weeks ago my 2K Maxima's SES light came on. My dad and I hooked up our OBDII Scanner and it said the code was P0171. We assumed that it was one of the oxygen sensors, so have not done anything about it yet. Now after hooking up the scanner again, it has also thrown the P0174 code. The car is running fine still, and the oxygen sensors are giving and output. Both of the codes deal with the two banks of the engine running to lean. After reading some other threads I think my symptoms look like the beginning of a MAF failure. Is there anyway to determine if this is the problem, or do I need tho check other things, such as the fuel pump, filter and Injectors.
#2
Here is a little more information to add to the problem. We cleared the codes a few weeks ago, it has taken them about 60-70 miles to come back on, so whatever the problem is, it is sporadic when the fault occurs. Before the codes came back on, we hooked it up to a OBDII scanner again. I was able to check the values that the MAF was reading. When the engine was cold, at idle it was reading .6 lb/min after the engine warmed up, it lowered to just under .3 lb/min. The values seemed to be stable and did not jump around very much. When a MAF is failing, is it possible for it to be functioning, but not consistently, or does it go from working fine to suddenly dying?
#3
Originally Posted by MattBeaty
Here is a little more information to add to the problem. We cleared the codes a few weeks ago, it has taken them about 60-70 miles to come back on, so whatever the problem is, it is sporadic when the fault occurs. Before the codes came back on, we hooked it up to a OBDII scanner again. I was able to check the values that the MAF was reading. When the engine was cold, at idle it was reading .6 lb/min after the engine warmed up, it lowered to just under .3 lb/min. The values seemed to be stable and did not jump around very much. When a MAF is failing, is it possible for it to be functioning, but not consistently, or does it go from working fine to suddenly dying?
#5
Originally Posted by MattBeaty
If I remember correctly, the long term fuel trim was right around -30 and the short term was -3.
#6
Thanks a bunch for the advice Menasor. My car does not have any engine mods and I am still running the stock MAF (61000 Miles). The O2 sensors are switching just like they should (One of them was replaced about a year ago), so I think that most likely you have hit the nail on the head with your diagnosis, thanks again.
#7
Originally Posted by MattBeaty
Thanks a bunch for the advice Menasor. My car does not have any engine mods and I am still running the stock MAF (61000 Miles). The O2 sensors are switching just like they should (One of them was replaced about a year ago), so I think that most likely you have hit the nail on the head with your diagnosis, thanks again.
#9
Originally Posted by YuAnChen
Got same code
SO is it maf ?
SO is it maf ?
#10
Its a MAF
If you get Nissan MAF ending in -AD200, which is countermeasure MAF for 00 Maximas, you will need updated reprogramming from the dealership otherwise you will get P0100 codes coming up.
If you get Nissan MAF ending in -AD200, which is countermeasure MAF for 00 Maximas, you will need updated reprogramming from the dealership otherwise you will get P0100 codes coming up.
#11
Before replacing MAF, SES P0171. Engine stalls after cold start.
After replacing MAF, SES P0140. Engine stalls at traffic lights, especially after warm start. I believe the MAF is an aftermarket AD200.
Would the updated reprogramming from the dealership resolve the problem?
After replacing MAF, SES P0140. Engine stalls at traffic lights, especially after warm start. I believe the MAF is an aftermarket AD200.
Would the updated reprogramming from the dealership resolve the problem?
#13
At 81,500 miles, my 2000 Maxima just posted a PO171 code _ Bank 1 system too lean. I've just read through your thread and was wondering if this is simply an oxygen sensor problem or something starting to go worse?
If it is just an O2 sensor, where is it located and would it be easy enough for a slightly mechanically inclined person to change it out?
If it makes a difference my car was set for California standards. I have seen problems with parts that mess up California made cars.
If it is just an O2 sensor, where is it located and would it be easy enough for a slightly mechanically inclined person to change it out?
If it makes a difference my car was set for California standards. I have seen problems with parts that mess up California made cars.
#14
The rascally car just decided to turn its SES light off by itself (PO171 code). Of course, that happened right after I bought MAF cleaner and throttle body cleaner and threatened the car with personal maintenance. I'll still clean the sensors since I have the cleaners. It doesn't look that difficult, even with my old hands.
Would this be sporadic in nature with a dirty Mass Airflow Sensor?
Would this be sporadic in nature with a dirty Mass Airflow Sensor?
#15
The rascally car just decided to turn its SES light off by itself (PO171 code). Of course, that happened right after I bought MAF cleaner and throttle body cleaner and threatened the car with personal maintenance. I'll still clean the sensors since I have the cleaners. It doesn't look that difficult, even with my old hands.
Would this be sporadic in nature with a dirty Mass Airflow Sensor?
Would this be sporadic in nature with a dirty Mass Airflow Sensor?
- Intake air leaks
- Front heated oxygen sensor
- Injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor
Last edited by maxiiiboy; 12-31-2015 at 01:09 AM.
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