HELP!! 96 xlt too lean codes.

[wildcat65gt500]

Ok so my exlorer has the bank1 and 2 lean codes. Symtoms are:

Occasional rough idle (rare)
After 15-20 drive time it acts like there is no power ie; I floor it and get nothing unless I barely touch the throttle then I get some power. (common)
Engine ONLY will die and then will restart with in a minute or so.(every day)

Here is a list of what I've done:

replaced MAF and IAC and O2 sensor (2months old both)
new upper and lower intake gaskets and all gaskets in between
new plugs and wires.
checked for vacuums myself and 3 other mechanics and nothing.
cat flow test.
Pressure on fuel pump is good according to ford but they didnt do a flow test.

Im leaning towards either the fuel pump or its relay, or the EGR and is solenoid (badly corroded).

Does anyone have other ideas that I may be missing?

 

[96eb96]

Ok so my exlorer has the bank1 and 2 lean codes. Symtoms are:

Occasional rough idle (rare)
After 15-20 drive time it acts like there is no power ie; I floor it and get nothing unless I barely touch the throttle then I get some power. (common)
Engine ONLY will die and then will restart with in a minute or so.(every day)

Here is a list of what I've done:

replaced MAF and IAC and O2 sensor (2months old both)
new upper and lower intake gaskets and all gaskets in between
new plugs and wires.
checked for vacuums myself and 3 other mechanics and nothing.
cat flow test.
Pressure on fuel pump is good according to ford but they didnt do a flow test.

Im leaning towards either the fuel pump or its relay, or the EGR and is solenoid (badly corroded).

Does anyone have other ideas that I may be missing?

Inspect the two rubber hoses to the DPFE.

If you plug the EGR valve nipple and the vacuum line you can eliminate that system. You will get codes but you shouldn't have the drive ability issues you are having.

Check that the egr works by applying vacuum to it and see if your engine stumbles, and then smooth when you release vac. That will assure your valve is working pefectly and stays shut.

You may have a bad DPFE(EGR sensor), very common. It could be tricking the computer into opening the EGR and causing these symptoms of a massive vac leak.

Eliminate the EGR first, its very easy to do.

See: http://www.aa1car.com/library/ford_lean_codes.htm

How about a fuel filter?

 

[robertoa1a]

What engine??? A '96 5.0 does not have a dpfe does it? It's a one tube pressure feedback system (one hose). 96eb96 5.0eb5.0. On the 4.0 I agree but he would most likely have an egr code as mine did.

 

[96eb96]

What engine??? A '96 5.0 does not have a dpfe does it? It's a one tube pressure feedback system (one hose). 96eb96 5.0eb5.0. On the 4.0 I agree but he would most likely have an egr code as mine did.

Did you ever hear of replacing U/L intake gaskets on a 5.0L??? That is how I guessed. The 96 5.0L I believe has the rear egr and sensor like in the 80s crown vics.

 

[BIGHVM]

Did you thighten the inlet manifold with a torgue wrench in the correct sequence- if not the manifold can distort and result in the same lean codes.

 

[robertoa1a]

Very good attn 2 detail. Cant get 1 past you. You never seem to have an off day. The old 5.0 intake is so tried and true gaskets are rarely an issue. So no.

Any hoo, my 4.0 gave an egr code when the dpfe went bad.

 

[wildcat65gt500]

Ya changed fuel filter. And yes it is a 4.0l. Ill pick up a dpfe from autozone and try that out.

 

[robertoa1a]

The parts people know that dpfe all to well. Very common problem. Heat gets to the electronics on the metal ones so they use a plastic unit for replacement. So I was told. Good luck.

 

[96eb96]

What engine??? A '96 5.0 does not have a dpfe does it? It's a one tube pressure feedback system (one hose). 96eb96 5.0eb5.0. On the 4.0 I agree but he would most likely have an egr code as mine did.

Not always. The sensor can fail in a way where the software does not see what it is doing as wrong and not trigger an EGR hard fault right away. The computer may want to open the valve 30% but the DPFE reports that the valve is only open 5%. So it increases the cycle to the vac solenoid until the DPFE says 30%, but in reality it is now 80%. The only code that the PCM will report is P0171/0174 and the truck will run like crap. There is nothing detectably wrong with the DPFE....


Ever get tricked by a salesman? Thats the idea . They just cause dollars to flow out your wallet.

 

[96eb96]

The parts people know that dpfe all to well. Very common problem. Heat gets to the electronics on the metal ones so they use a plastic unit for replacement. So I was told. Good luck.

I suggest either a small hose clamp OR two tight wireties on the rubber DPFE hose where it attaches to the nipple. Also its a good idea to cut off the old section (maybe 1/2") where it attached to the metal dpfe or get new hoses for $5. There are cases of hoses slipping off off the plastic fittings and destroying the DPFE with an exhaust blowtorch. They are under slight pressure..

PS..heat does not kill them normally. The air between the exhaust and the sensor is static air and is a great insulator, like closing an A/C vent in your house, or double glazed windows.

Moisture does them in.

 

[KPT]

Ill pick up a dpfe from autozone and try that out.

DO NOT get a parts store DPFE. It will fail quickly. Get the OE part from one of the online vendors.

 

[96eb96]

DO NOT get a parts store DPFE. It will fail quickly. Get the OE part from one of the online vendors.

Yeah, 2nd on that. If you search around it is $50 for the 96 4.0 at the lowest.

 

[wildcat65gt500]

ok lets add to the list code p302. missfire in cylinder 2. Probably just a symptom of lean codes. So here is what it is doing now.

Running VERY rough (missing) when I have it at 1/3 throttle it bogs down and when I floor it , it REALLY bogs down untill it stalls or dies. The Fuel pump turns on when I start it but it sounds very weak like when you put too low of voltage to a motor (like rc cars) and instead of a fast whurrrr it is low and slow and it doesnt stay constant.

Are these fuel pumps either they work or they dont, or could it possibly be barely on? Oh btw dpfe was replaced also and confirmed that the EGR works as it should.

 

[Steviski]

I've also been plagued by bank 1 and bank 2 lean codes. I've been trying to avoid alot of the work mentioned in previous posts.

I change my oil every 4-5000 mi. A few oil changes back, I put a can of Restore in, cleared the code and was good for about 6-8mn. Until they popped up again.

I changed the oil again after about 3000mi and added another can of restore and cleared the codes. Unfortunately, they came right back. I was pretty dang irritated.

So I lived with the codes for about another 8-10mns until my next oil change. I went through the same process and yup...the codes returned.

For about a week I cleared the codes and they returned. At this point I'm pretty sure I have no choice but to take some more intrussive measures.

While standing over my engine shaking my head, I just happened to notice my Oil cap was slightly ****ed to the side. I checked to see if it was tight and it was.

I removed it and retightened, only to see it was ****ed to the side again. After a few attempts, I was able to align the cap and secure it properlly.

Just for kicks, I disconnected the battery cable for a few mins and reconnected. It's now been several months, the codes not returned and the truck appears to be running much smoother, as it should.

I can't guarantee something this simply will fix a similar problem for anyone else. I just thought it was worth posting.

 

[wildcat65gt500]

Well I think I have it narrowed down to a couple of things now. We were board and since my XLT is on blocks we decided to try a different approach. Forget the CEL and just look at the symptoms (I watch too much House). So judging by how it had been driving we felt the exhaust was clogged some where so we pulled the cat off and low and behold it runs perfect (sounds GREAT too) and OMG the CEL went off. So it is either the cat, O2 after the cat or the muffler. YAY Im so much closer to having my baby back. Ok carry on.

 

[wildcat65gt500]

Ok well it seems my Cat is toast. I refuse to pay 300+ for an OEM cat so has anyone done a universal cat for a 96 XLT with the 4.0 (has the 2 CATs) and still pass emissions? My father inlaw just wants to basically get rid of the inside of the cat to run basically a straight pipe but look like a cat too. I dont have easy access to welding equipment but if it saves me a few hundred bucks ill make a way. PLEASE HELP! And thanks in advance.

 

[wildcat65gt500]

Ok Im ready to drive this thing off the nearest cliff.

Here is a list of the most recent codes pulled.
P0300 and P0304 (misfires random and now on #4)
P0171 and P0174 (lean on banks 1 and 2)
P1151 (not much of a clue what it could be.

I have eliminated the cat from the problem via a "test pipe". Test pipe on and still acts the same.
Once it is warmed up it starts to bog down when I get on the gas more than 1/4 peddle. Limp mode I would venture to guess. Upon further investigation I have realized that when I replaced the passenger side O2 sensor in the front that I replaced it with the one that was specifically for the after CAT sensor (not sure if it makes a difference).

This is driving me nuts. I am completely stumped as is my father inlaw. We checked fuel pressure by basically taking a piece of hose and a pressure gauge and putting it on the pressure relief valve and got 30ish psi iirc.

Someone please help me I just want my truck back.

 

[wildcat65gt500]

911 desperation.

Ok Im ready to drive this thing off the nearest cliff.

Here is a list of the most recent codes pulled.
P0300 and P0304 (misfires random and now on #4)
P0171 and P0174 (lean on banks 1 and 2)
P1151 (not much of a clue what it could be.

I have eliminated the cat from the problem via a "test pipe". Test pipe on and still acts the same.
Once it is warmed up it starts to bog down when I get on the gas more than 1/4 peddle. Limp mode I would venture to guess. Upon further investigation I have realized that when I replaced the passenger side O2 sensor in the front that I replaced it with the one that was specifically for the after CAT sensor (not sure if it makes a difference).

This is driving me nuts. I am completely stumped as is my father inlaw. We checked fuel pressure by basically taking a piece of hose and a pressure gauge and putting it on the pressure relief valve and got 30ish psi iirc.

Someone please help me I just want my truck back.