I have had this code come up, and my fuel mileage has dropped. The people at Advanced Auto said fuel mixture too lean, but I have read all sorts of other things here.

The engine light came on after I started having issues starting the car. It would crank but not fire, I would turn the key off, then try again, and it would start right up. And I would smell gas for a minute.

Is this an injector issue, is this just needing new spark plugs, or does it just need a swift kick in the ass? I just got this car, I am a little frustrated.

 

It is usually either a stuck EVAP canister purge valve (the one under the hood) or the fuel pump.

This case sounds like fuel pump. You need to have The fuel pressure checked.

The EVAP valve can be checked by disconnecting it and blowing through it, if it let's air through it is bad.

 

I just checked the purge valve, I was not able to blow through it, which as I understand is a good test. When the car starts, it runs great. I have lost a couple of mpg though.

I was running 87 octane, until I read on here that the 2.4 wants something a little beefier, so I went to high grade. Its only been half a tank so far.

 

Most likely the fuel pump then.

 

Naturally it would be a very expensive repair. I dont have the facilities to drop a fuel tank, so with the $190 fuel pump and probably 300+ for the shop, thats just awesome.

 

You can check the fuel pressure first. A fuel pressure gage from Harbor Freight costs $20-$30. A good mechanic would Maybe do it for free. You don't need to go to GM or any Name Brand shop, I. Would stick with an independent.

 

I'll definitely stick with an independent haha! Its not under warranty, and I have a guy that I trust. I'll pick up a fuel pressure gauge on payday. Seems weird that fuel pump would be it, it runs great after the initial starting issue, which is about 75% of the time, I mean, no stuttering or anything, runs like a scalded dog.

 

In addition to the pressure you need to leak test the check valve in the pump. Without it there is no fuel in the rail at start up. It is integral to the pump.

 

I am having the same cranking problem (3-4 tries) and P0171 code. When it starts, it smells exactly like lighter fluid. However, I am having other symptoms and driveability issues:

• pulsating and surging as I drive (mostly rhythmic, almost 2 pulses per second)
• greatly decreased fuel mileage and power
• "low fuel" warning even when tank is half full
• display indicating 13 mpg when I am getting 18

All of this began suddenly while driving on a rainy day with 3/4 tank of gas. Running that gas out and putting in new gas from different stations has made no difference. Fuel level makes little to no difference. Initial code read also indicated knock sensor, but it hasn't re-set, and I assume it detected a knock when the car was sputtering upon trying to start.

Pressing the Schrader valve on the fuel rail immediately after turning off the engine yields nothing (no fuel or air comes out).

From what I have read, it appears I will have to replace the fuel pump, since it appears the system has no serviceable parts or filters before the fuel rails. Am I right about this? I have found a "fuel tank pressure sensor," but I understand it has to do with the EVAP/purge canister and not the fuel pressure regulator. Can someone kindly confirm this?

 

Welcome to the site.

You are correct. The fuel tank psi sensor is only there for the computer to test the fuel evap system.

It has nothing to do with you drivability issue.

It sounds like you need a fuel pump but I would recommend renting or buying a fuel psi gauge to confirm the fuel pump failure before you replace it.