P0171 & p0174 Codes on 3.0 Ranger

[00ranger3.0]

Hello Everyone i'm new to the forum. Tried to get some help on the urgent section but no luck yet.

My Truck info:

2000
Ranger
3.0 4x4
Auto Trans

I just picked up my Ranger and love it. I've done a ton of work that the truck needed as it sat nearly a year before i bought it.

The issues ive been having from the beginning of buying was P0171 & P0174 codes.

stuff ive replaced so far some not related to the codes.

Upper and lower intake manifold gaskets.
Valve Cover Gaskets.
IAC and gasket.
Cleaned MAF.
Egr tube was busted off at exhaust so i replaced that. (didn't replace EGR)
Cleaned the Throttle body out.
Pcv Valve & hose
DPFE Sensor
Plugs & wires (motorcraft)
Brakes (ALL)
Hubs
T-stat
Flushed Fluids
(More but forgetting)

After replacing all (evap Equip) i still noticed a very high idle

Did a smoke test and found 1 major Vacuum Leak which was insanely weird.

Someone had drilled several small holes in the brake booster Pressure relief valve. and it was sucking in air like crazy. No Idea Why someone would do that?

Did another smoke test as well as sprayed Brake Cleaner everywhere and there isnt anymore Vac leaks.

As of now engine is running great idle is around 900 Rpm which is good enough for me. much better then 1600 with the Vac Leak.

I have obd2 reader but its not a very advanced one.

Not Sure if it helps but

The P0174 Data is:

Fuel Sys 1-CL
Fuel Sys 2-NA
Calc Load %-64.71
ECT (C)-77
STFT B1 %-6.25
LTFT B1 %-25.00
STFT B2 %-8.59
LTFT B2 %-25.00
Eng RPM-2427
Veh Speed-57

No data on the P0171 Right now as i reset and it didn't come back on yet.

Any Recommendations would be great.

Thanks in Advance!

 

[Rearanger]

How long after fixing the vac leak did you take the scan readings?

LTFT shows large vac leak. STFT pretty much useless as one number as it shifts above/below zero from O2 signals. If you have O2 data access that would help.

Without real time data (graphed is best) it's hard to know what's going on. You should look at idle, 1500rpm, 2500rpm. There are some really good fuel trim videos on YouTube which you should watch.

 

[00ranger3.0]

About a day later i took the scan readings. ill have to check out some of the youtube videos unfortunately my scanner is a bit limited to what it can/will do so i might have to either get another one or see if someone i know has a better one. Would a damaged Fuel tank filler neck send a high LTFT reading? Not sure if its damaged or rusted but will take a look at that. I've heard that that's a common problem on the rangers also. Other then that im going nuts looking for another Vac Leak.

 

[Rearanger]

Would a damaged Fuel tank filler neck send a high LTFT reading?

If so you should get an evap code pretty fast. I believe the only connection to the intake from the evap is from the charcoal canister. There should be a valve that is normally closed but which opens under certain conditions to burn excess fumes.

You really need to look at STFT, LTFT, O2 signals to get full picture.

If you have a smoke machine you're lucky.

 

[01b3000ds]

the filler neck is an easy swap. 3 screws, 2 hose clamps. I think it took me half an hour.

 

[00ranger3.0]

I'll have to look into getting the STFT and LTFT Readings as my scanner won't do them live. Only when the check engine light is on. I did replace the 2 upstream O2 sensors just for the heck of it to and same thing.

The codes does came back fairly fast. 1 usually faster then the other. It just doesn't trigger the actual check engine light. It's a soft code and doesn't illuminate the light until a couple more engine starts or a few more miles down the road.

 

[00ranger3.0]

Just pulled some more info up but it's not live information
Might help. Not sure. Can't get any information from the 0174 code

P0171
Fuel sys 1- CL
Fuel sys 2-NA
Cal load %-76.47
ECT -79
STFT B1%-10.94
LTFT B1%-25.00
STFT B2%-11.72
LTFT B2%-25.00
Eng rpm-2594
Veh speed-61

 

[Rearanger]

If that info was in memory then that tells you what conditions were when code was set.

 

[adsm08]

STFT pretty much useless as one number as it shifts above/below zero from O2 signals.

That's not really true. The short trim can tell you quite a bit about if a leak is there or not. If you clear the memory and start the engine while watching the short trims will tell you pretty quick if there is a leak. If there is it will shoot up to 15% quickly. If there was a leak but it's been fixed the short trim will stabilize around 5% and then switch around zero as the long trim adjusts.


But adding the long and short trims together at idle and 2500 RPM, then taking the difference of the sums is the best way to determine if there is a leak.

 

[Rearanger]

That's not really true.

You've got way more experience than me, but what I meant was that unless you see live data of the change there's not much use. One data point captured on short term is not much help - I'm thinking.

 

[adsm08]

You are correct that just the one point recorded on freeze frame, by itself is worthless. You do need to be able to see a live graph to be able to make any use of the information.

 

[00ranger3.0]

I'll Try to get someone with a scan tool with capabilities of live data. I'm going nuts trying to figure this out and ive already done most of the basics + Some. I know the truck sat for a year tho. i do have a question for you guys tho.

Just for kicks i took off the EGR Vac Line today and it made absolutely no change at all. i was kinda curious as to if i had bad EGR valve. Should i have seen any type of response in idle or engine running conditions when i removed the Vac connection? Wondering if the EGR could be a main culprit in the Codes.

thanks again guys.

 

[Rearanger]

At idle the EGR is closed, so taking off the vac line would do nothing. The EGR can be a source of vacuum leak if not closing, usually due to crud build up. If the EGR is opened during idle the engine should stall.

They need cleaning from time to time and it would not hurt to remove it and clean it.

 

[01b3000ds]

<flame suit on>

After seeing this page

http://www.motorcraftservice.com/pubs/content/~WVS2/~MUS~LEN/14/VS21013.HTM

I'm of a mind to defeat the EGR system entirely. A Programmed, designed-in leak of up to 12 or 13" of vacuum, really? I wonder what that does to efficiency?

wouldn't an actuated/open EGR divert unburned hydrocarbons away from the upstream o2 on that bank, making the ECU think it was running lean? that's hypocritical, considering EGR is part of the "Emissions Control" on modern fuel injected engines, don't you think?

Sure, the warm air theoretically displaces colder intake air, keeping the air-fuel ratio "optimal", but what if textbook/theoretical optimal and real world optimal are two very different things? I mean, we wouldn't be as aggressive on the gas pedal if we didn't need to, and that would lower emissions from less use of gasoline, ESPECIALLY since there are speed limits.

Ok, maybe I'll just crawl back under my rock and not stir up the pot (or take the thread WAY off topic lol)...The government knows best, after all.

I'll keep you posted on what happens once I try this on my 01 with 250k miles...good and/or bad.

 

[00ranger3.0]

01b3000ds

you on to something... and ive heard/seen many 6.0l Diesels doing an EGR delete. but for me im just trying to figure what the hell is going on with my 0171 & 0174 codes. im almost at my breaking point. I may just break down and take to to ford or another shop with the capabilities of running a full diag with an advanced 0bd2 scanner unlike mine.