p0171, p0455, p0456

[NismoFire]

p0171 Fuel Trim Lean (Bank 1)

p0455 EVAP Gross Leak

p0456 EVAP Very Small Leak




Pulled these codes about 2 weeks ago, just now getting around to looking for the problem. Dropped the spare tire today and checked the lines going in/out of the EVAP canister, all were good. We could hear the whistle but couldn't locate it on the underside. Sounded like it was coming from the passenger rear wheel well, so I pulled the inspection cover under the back seat and sprayed the FSU. Sure enough, bubbles. Looked like a scene out of Finding Nemo under there.


This O-ring should have been replaced when the FSU was replaced 3 years ago when the recall was fixed. It doesn't look like the bolts going into the FSU have even been touched since Jan 2002 when the truck rolled out of Smyrna.



Do I stand a chance of taking it to a more reputable dealer and having it repaired there under the original recall, or dare I spend $12 and try not to get all the corrosion/dirt/gunk into the fuel tank? I'll get pics later of how nasty it is.

 

[NismoFire]

Talked to the @$$hole at the dealer this morning. There are 2 guys that I normally deal with- 1 is a jerk, the other is the best thing that ever happened to the Nissan of Murfreesboro Service Dept. I lucked into talking with the jerk. I think he worked for the dealer that did the recall to begin with.


Gonna do this myself. Lucky me. Thanks for all the help!

 

[Prime]

Just noticed this thread.

If there was something that should have been done as part of a recall and it wasn't, I'd be raising hell with the service manager.

I hate messing with fuel systems. It's always more trouble than its worth. Something like that I'd gladly pay someone else to deal with it.

Any clue why you're getting the lean code?

 

[NismoFire]

The lean code cleared itself. I'm guessing it had something to do with having too much air in the fuel tank bumping up the pressure in the rail.


USPS literally just delivered the O-Ring. When I get the tank emptied of gas, I'll start the project.

 

[NismoFire]

Bumping this again. P0171 is back.

SES went out completely about 500mi after the O-Ring was replaced. Comes back on for a few days then goes away for a week. It's been on now for over a month.


AutoZone's handy little printout tells me the following:

Fuel System Lean Bank 1 probable causes:
- Low Fuel Pressure
- Blocked injector(s)
- Large vacuum leak
- MAF sensor fault



Any more ideas?

 

[Prime]

Given the description, I'd suspect vacuum leak.

 

[NismoFire]

Given the description, I'd suspect vacuum leak.

I've looked for that leak for months. I can't find it anywhere.

Would the intake hose throw that code if it was cracked around the plug from the resonator delete?

 

[Prime]

Yeah. Any air that gets in behind the mass air sensor is considered a vacuum leak.

 

[Tay-Lo]

Was there any final conclusion on the P0171 code? I started getting it yesterday.

 

[granitex]

The sending unit and pump for that matter are not bad to change, but you may need to smoke test for the small vac leaks, hoses dry out over time and even a pin hole can cause issues.