P0171 P0174 P0455

[pjm]

Need some help from the guru's here please.
Have codes for both banks lean and major evap leak.

There have been no codes for two weeks, and the engine still seems to be running fine. Idles great at about 1000 rpm. Then today all three of these codes at the same time.

I have searched for hours on this site and have chased this problem(s) for weeks. I've found great advice and here's what I've recently done:

New lower, middle and upper intake manifold gaskets - helped
New plugs - #4 had a broken insulator and was misfiring
New DPFE
New IAC
Cleaned and lightly oiled air filter
Cleaned MAF sensor
New PCV - checked hose, no crack, no crud inside
Checked all vacuum lines - no leaks apparent
New Ford OEM gas cap

Is there anything else I can check before I bring it to the shop?
thanks

 

[MountaineerGreen]

Above your spare is your charcoal canister- check the hoses that connect to it and check the valve attached. Check your fill hoses and clamps- a real pain to check on top of the tank. In your drivers side fenderwell, there are a pair of solenoids that are a part of your evap system. One hose in particular tends to dry rot pretty badly. The P0455 is a tough code to track down- I've been battling it for a while.

 

[budwich]

your idle is too high... indicating a leak somewhere... the suggestions are good. Further try spraying various areas with carb cleaner to see if the engine stumbles for leak detection assistance. Have you filled your gas tank lately as in "full filled"?... just in case it is got a leak somewhere. My bet is on the area under the battery tray as suggested.


Having read further, my bet is on the EVAP cannister purge valve... either valve itself or the vacuum line going to it is fubarred.

 

[Turdle]

Below the battery tray-is a evap solenoid. They will often get battery acid dripped on them and develop a leak-or it could be broken. I would check this out. You may need to pull it off and check the hoses real well. You can see it in the front of the driver side wheel well.

 

[pjm]

Update

First, thanks for the tips.
The truck has been running pretty well, except for lousy mileage you'd expect with the trim maxed out.
I finally found the time to pull the spare and check out the purge valve. As far as I can tell, the hoses look fine, no cracks or brittleness to speak of. There are hard lines from the gas tank almost all the way to the canister, then just a foot of vacuum line to the cannister.
It's the dual cannister model under a bang plate, with a connector inbetween. There was no visible cracks anywhere I could see on either of the cannisters. I guess I'll just replace the purge valve because it's only 20 bucks. The fill hoses look ok, a little rusty but no cracks.
Think I should do that, reset the codes. Then see if they come back, if they do, then it's gotta be the thingamajig under the battery - which I think is an obsolete part.
I'll post another update when I resolve this, and of course appreciate any feedback in the meantime.

 

[pjm]

Follow up question

Does anyone know what the air management diverter valve does? And if it malfunctions, could it cause the above codes to be set? What are the symptoms of a broken one? I've searched and there's not much on this site that i can find.

 

[pjm]

Found it - I think

Tried spraying carb cleaner around intake manifold and egr. Looks like I've got a leaky seal where the egr tube goes into the intake manifold.
Local dealer had one - $10.
Will swap out tonight, reset codes and see how it goes.
thanks again for the tips

 

[travelinman1962]

Codes

Im not a guru but i did have this problem with both banks running lean in the fuel rails. Had a diagnostic done and it turned out the tube going from the egr valve to the intake manifold was leaking right where it meets the manifold and fixed it. Low and behold the codes haven't shown up again. Run the engine and spray carb cleaner at that area to see if the idle changes, if it does it means its leaking at that area. Be very careful not to get it on a hot exhaust manifold. Good luck.

 

[travelinman1962]

Oops guess you found it.

 

[alohamonte]

is the EVAP leak an environmental issue or a performance one?

 

[Cobraguy]

environmental. But you won't pass emissions without it working properly.

 

[Fantasymon]

I have these same 3 codes popping up.

The Ford dealership wants $85 to "diagnose" the problem. Assuming they can tell me exactly what the problem is, I think that is a fair price. I'm sure this will be followed by a $1,000 repair quote.

Anyhow, if this is an environmental issue, will it not affect gas mileage? I swear I am getting really bad gas mileage lately.


I did a "custom" piping from my air filter to the throttle body...Could a leak here be causing any of these?

How worried about these codes should I be? I've lost 40K in stocks/IRA's the past 2 weeks so money is tight.

Thanks,
Grantp

 

[budwich]

I don't think your "custom piping" is a source of these codes. How serious... hmmm, the egr typically is only an emissions/environmental issue so you choose your "poison". HOWEVER, any leaky associated with the vacuum "supply" on an engine will affect its performance and may show up as lower gas mileage. Why not follow the info in the thread and do some "custom DIY" troubleshooting instead of paying the dealer.

 

[nunn01]

my husband is working on a 1998 ford ranger with a 3.0 engine and needs to know what the torques is on the lower intake manifold please help it would be a blessing for me thank you

 

[post009]

i had the same codes for my 96 XLT I'm still fighting the EVAP leak but the bank codes that said it was running lean turn out to be the fuel pump. you might wanna check it out