My check engine light recently went on in my 96 Nissan Maxima. All of my fluids are topped off. I checked for oil leaks a couple of weeks ago and didn't have any (although there is no guarantee that this hasn't change...I will check again). I have the following diagnostic trouble codes (DTCs):

P0171: System too lean (bank 1)
P0174: System too lean (bank 2)
P0325: Knock sensor 1 Circuit Malfunction Bank 1 or 1 Sensor
P1447: EVAP Emission Control System Purge Flow Monitoring

I have the service manual which talks about what could be wrong for each DTC. Does anyone know what could be wrong that would cause all four DTCs? Which DTC diagnostic procedure is most likely to reveal the root cause?

Thanks so much!

 

http://www.boredmder.com/ecucodes/

 

I wanna be the first to say it.....The knock sensor code is a ghost code so take care of all the other codes first!! lol

 

I'm going to guess that you have a large leak in the evap system, causing a lean condition and ghost KS code. check all the evap hoses first. Possibly bad purge control valve.

 

Correct P1447 first and then clear all codes. If P0171 and P0174 return, you may have a problem with your injectors.

 

Agree..

 

have you replaced you spark plugs lately? jw buddies 96 max done this told him to change plugs first and BAM fixed it was saying the same thing just didnt know why it didnt throw a misfire code instead but hasent had the codes pop up since and thats been 4 months but might help ya out everyone knows our maxima's have a mind of there own