Joseph Tator
Active Member
That will be my next step. Thank you
Frustrated 01 xlt 5.4
- Thread starter Joseph Tator
- Start date
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That will be my next step. Thank you
Take a look at this discussion - 2000 Expedition 5.4 4x4 P0171 & P0174
You will know that you're definitely not alone. Where did you get the intake manifold done or did you do it yourself? Did you use a Ford or aftermarket manifold? You'll see from my posts on that string that I chased p0171 and p0174 for six months. I shot cans of carb cleaner around anything that I thought could suck air and put soapy water to look for bubbles on anything I thought could leak air. I finally let the dealer diagnose it after some of my "fix by replacement" and they found the cracked intake manifold in the back near the firewall where I never would have seen it. I let them fix it and haven't had any issues in the 85,000 miles since. I have 295,000 miles now. I didn't replace the manifold myself because I thought I'd induce more vacuum leaks than I would cure. I did replace many hoses, the brake booster, and anything else I thought could be leaking air. It was none of those things. My COPs are original, as are the O2 sensors, water pump, and fuel cap. I changed the MAF once but shouldn't have. You can easily clean a MAF with electronic spray cleaner and I've been doing that for years on all my Fords every 25K miles when I clean the K&N air filters. I change my fuel filters every 30K (except on the '11 Expedition, which has an in-tank filter), so I've never thrown a code that was fuel filter related. The fuel filter is a cheap thing to replace (though it can be a pain, as mentioned above). Do that next and if that doesn't help I would think you still have a vacuum leak. Pay Ford to test it before you spend even more money doing "diagnosis by replacement" if the fuel filter doesn't help. An hour on their analyzer would be cheap money in comparison.
You will know that you're definitely not alone. Where did you get the intake manifold done or did you do it yourself? Did you use a Ford or aftermarket manifold? You'll see from my posts on that string that I chased p0171 and p0174 for six months. I shot cans of carb cleaner around anything that I thought could suck air and put soapy water to look for bubbles on anything I thought could leak air. I finally let the dealer diagnose it after some of my "fix by replacement" and they found the cracked intake manifold in the back near the firewall where I never would have seen it. I let them fix it and haven't had any issues in the 85,000 miles since. I have 295,000 miles now. I didn't replace the manifold myself because I thought I'd induce more vacuum leaks than I would cure. I did replace many hoses, the brake booster, and anything else I thought could be leaking air. It was none of those things. My COPs are original, as are the O2 sensors, water pump, and fuel cap. I changed the MAF once but shouldn't have. You can easily clean a MAF with electronic spray cleaner and I've been doing that for years on all my Fords every 25K miles when I clean the K&N air filters. I change my fuel filters every 30K (except on the '11 Expedition, which has an in-tank filter), so I've never thrown a code that was fuel filter related. The fuel filter is a cheap thing to replace (though it can be a pain, as mentioned above). Do that next and if that doesn't help I would think you still have a vacuum leak. Pay Ford to test it before you spend even more money doing "diagnosis by replacement" if the fuel filter doesn't help. An hour on their analyzer would be cheap money in comparison.
Had the exact issue with mine for over a year, changed parts, smoke test, soap test, filter changes, fuel pressure idle and leak down test....ended up being the fuel pump. Held pressure at idle and leak down passed, but from 1500 to 3000 rpm, a major drop in pressure. Never knewof a pump to die so slowly. Replaced the pump and havent had the codes or the power loss since. Fuel pressure test is where i should've been before the part swapping.
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Sgt8706
New Member
Same codes here. '01 5.4 141k. However with my codes I've cleared them and they do not come back unless the temp drops to 25° or below. Once the worst of the winter passes it's fine. I am now starting to have an issue with the truck being fine for days then just cranking without turning over at all them letting it sit for 30min or so and it fires right up.
Bedrck47
Full Access Members
If you are now having other problems you should start a new thread dealing with those problems not with someone else's problems You will get better responses
Sgt8706
New Member
Thank you Bedrck47
J Hairston
New Member
PCV elbow. google the codes, lots of f150 and expedition owners had same issue
1955moose
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Well this is getting fun! The fact that you've got a rock steady idle at 600 rpm, would lead me away from intake manifold, pcv rubber elbow, or anything that's vacuum related. Did you swap out manifold because of the 171 and 174 codes? One thing you didn't mention in your op, is how does it run! Strong with good power/torque, or is it down on power, stumbling, missing pulling up grades? Be more specific please!
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Just for the record, I had a rock steady idle also --- just codes & the SES light.
The PCV elbow was failing but only a small hole, until I touched it
