My z is running really bad and service engine light came on. I ran the code scanner and it gave me these codes. I need some serious help. P0171 P0174 P0300 what do they mean and how can I fix the problem.

 

http://www.obd-codes.com/trouble_codes/


P0171 = System too Lean (Bank 1)
P0174 = System too Lean (Bank 2)
P0300 = Random/Multiple Cylinder Misfire Detected

On these types of situations Google is your friend, at least for researching what the codes mean.

As for where to start, have you checked plugs, coils and injectors? Was the car recently modified or serviced?

 

There have been no modifications made to this car at all its 100% stock. Before I got these codes about a few weeks ago it gave me the O2 sensor code but it went away. What would you say the problem would be?

 

QFT

 

You might have a Vacuum Leak? Or fuel pump going weak??

 

P0300 might be leaking valve cover seal right rear spark plug. Atleast that's what it was for me. From what I've read it's a fairly common issue.

 

im having the code P0171 aswell and i thought the same thing cause my MAF failed completely i replaced it no more AIT error or air metering code but its throwing a P0171 lean code.. its only got 57k miles on it and the car is babied i never go over 4k rpm when driving..i know there isnt a vac leak all the hoses are still very flex able and look new non have dry rotted. im geussing my fuel pump is going out or the filter is crap

 

Some please help!