The truck seems to run fine unless the temps drop below 10. Then it runs really ruff at slow speeds and will kill while stopped at stop lights. I have a antifreeze leak that I am getting fixed on Wednesday, also only leaks when it is below 10. Could these 2 problems be related or do I have 2 seperate issues?

Thanks for any help

Dan

 

Very well could be.

What motor do you have?

 

I have the 5.4. The leak is coming from the manifold on top of the engine where the heater hose connects on the front of the passenger side of the engine. It is a pretty steady drip so I am taking it to the mechanic tomorrow to get the manifold replaced.

 

0171 and 0174 are indicating a lean condition. If you are having problems with your manifold and unmetered air is getting in that could cause those codes.

 

I just had somebody tell me that a bad air filter can cause a problem that simulate a bad MAF. And output these codes. I just replaced the air filter a few weeks ago could I have gotten a bad one? Or are they just feeding me a line?

 

A bad air filter should not force those codes, they are lean codes. Plus the air filter is in front of the MAF, so the MAF will adjust for the air flow comming through the filter. They must have meant a bad fuel filter.

Those codes are commonly caused on the 5.4's from a bad PCV hose at the back of the throttle body. That is a good/cheap place to start.

Lean codes are most often caused from an air leak after the MAF (Mass Air Flow sensor) because all the incomming air is not measured by the computer. So when the exhaust is measured by the O2 sensors they see more air than the intake has measured, which is your lean condition (lack of sufficient fuel).

There are other things that can cause those codes too, but stick with the most common solutions, which would be a vac leak some place.

Good luck. Hope that helps to 'splain it for you a little.

 

Thanks for the reply, I will pull out the chilton manual this weekend and start with the vacuum hoses.


Thanks

Dan

 

Checked the vacuum hoses on throttle body they look good no visible cracks. I noticed that the boot that goes around the wiring harness on the MAF was almost pulled out of the hole. If that was leaking air, could that be the problem. I am going to keep looking at hoses to see if I can find one that looks cracked but in an unheated garage and 10 degree temps it is slow going.

Thanks for all the help

 

Yes it can. You need to have a sealed system from the air cleaner to the throttle body.

Hope that's it for ya!

 

Found a cracked vacuum hose on the bottom of the piece in the picture. It looks like it eventually runs down to the exhaust, maybee the o2 sensor?. Unfortunately it is to short to cut to get rid of the crack. Any idea on the diameter of hose that I will need to get to replace it? I duct taped it and then ran electricians tape around that as a temp fix.

 

That looks like your DPFE, that could be the source of the problem. It's part of the EGR system.

Plus I think that is special hose. You need to get a replacement hose for the DPFE, I don't know if it is an auto parts store part or dealer.

 

Just did a quick google search and it looks like it needs a special high temp hose. Hope my tape job doesn't cause more damage before I can get it fixed. I will let you know if my problems go away.

Again thanks for all your help.

Dan

 

Both just came up on my 03 F150 HD Supercrew with the 5.4 Supercharged engine
I've notice a ticking that sounds like exhaust coming from the drivers side but been unable to isolate this. Could and exhaust leak before the 02 cause it as well.

 

An exhaust leak close to the 02 sensor will/can give you a lean code for that side.