95 E150: 351w

Similar thing happened a few months ago. I just had the codes, but non of the symptons.

Also, there was 1 time during the summer, where I went to fill up gas. It was super hot and my girl friend asked if we can leave the car on while I fill up. So we left the car on while filling up with A/C and when I went back into the car, I noticed that the p0171 and p0174 CEL was on. No symptoms at all.

I cleared the codes and it hasn't come back since a few days ago. No symptoms at all from the previous lights.

So

A couple of days ago I got a P0171 and P0174 code. Right before this it felt the throttle wasn't opening up all the way or there was low fuel pressure. On the highway I would have to press down on the gas a lot to get some speed. More than before the code popped up.

So I kept driving. I parked and when I got back in and started, I got a really rough idle. Almost to the point of stalling. I tried revved the engine a little, it got better but when back to the rough idle. I turned the van off and waited a few minutes while I ate my lunch.

I then turned on the van and the idle was slightly rough. I thought it would be okay so I started driving. It started stuttering real bad at low rpm while I was exiting the parking lot and I heard a very loud squealing noise underneath the driver's side (lasted 1-2 seconds). I just kept plowing on and the car drove fine for 2 hours.

When I got home that day I cleared the codes and left the van alone for a couple of days. This morning, I went out to see what I would need to buy to fix the problem, but now the van seems ok and back to its old self.

The van has had an exhaust leak on the passenger side since I bought it 2 years ago. I probably need to change some O2 sensors, other then that, is there anything obvious about my experience? Anything specific to look for before?

I had fixed the exhaust leak 2 years ago, but the repair only lasted about a year.

Thanks everyone. Hope ya'll had a good Thanksgiving.

 

I believe those are lean codes for right and left bank, O2 gives a straight up O2 code, but that was on my 99 E350, wound up being my plastic intake tubing from the MAF to the TB, non metered air getting in making it impossible for the engine to inject the correct fuel for clean burn. Now I have no idea if the 95 had MAF, I thought they were speed density, yet you could check your intake, rent a fuel pressure gauge so you can at least rule that out, fuel cools the pump as it's submerged in it, the lower the fuel in the tank, the hotter it runs, if it quits running, yet will start up after sitting only to repeat it usually means bad fuel pump.

 

Thanks for the reply.

This reminds me that every time I fill gas, a little bit of gas leaks. I can see drop dripping from the filler neck. I always assumed that there was a tiny crack or something in the neck and losing a few drops during a fill up didn't bother me.

Can air get into the system that way?

 

96 351w

So I had a PCV hose snap on me and fixed it.

I assumed that at one point it was cracked and that was what was causing my P0171 and P0174 codes.

But after about 1000 miles. The codes showed up again.

I noticed that I lacked some power going up hills. Had to turn off OD numerous times at places where I didn't need to before.

Last week, I had a shop do a very thorough smoke test to check for additional vacuum leaks and fuel pressure test.

No vacuum leaks and fuel is 30 psi. Mechanic says low end but within specs.

Can an exhaust leak cause these codes and lack of power? Should i be worried about clogged cats or fuel pump that is starting to fail?

 

Problem is found.

DPFE sensor was out of spec. Replaced it with a new part, which is plastic instead of metal like the original.

Now I am getting a high pitched intermittent whine from the fuel pump during operation.

Codes hasn't come back.

Gonna bite the bullet and swap out the fuel pump and I think I'll be good for a while.

 

Did you replace the fuel filter? When dirty they restrict fuel flow and cause these symptoms.

Also, if you are changing the pump check the filler and vent hoses. They are notorious for cracking and leaking. You can buy a replacement from Rockauto.com