I have codes po171 & 174 again.
2004 Ford F-150 Heritage

I have codes po171 & 174 again.

(2004 Ford F-150 Heritage)
Its been checked with smoke and nothing. It runs great but when im on the hwy for awhile and push the peddle to the floor it just goes flat nothing no power. I changed the fuel filter, plugs and pcv hose it had a hole in it. I reset it and the light comes back in about 10 miles or so. Code 174 always comes on first to lean bank 2. Im lost help.
3 answers & 3 comments
Popular Answer
on January 02, 2015
I had the same problem it was the isolator bolts. Here is a link that worked very easy fix. https://sites.google.com/site/fordf150p0171p0174fix/P0171P0174-Fix
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on January 03, 2015
Well I did what you said and wow it worked no more check engine light and it runs a lot better. I sure do thank you and so doz my truck. The parts ran about $75 and it took me about 4 hours thanks again.
General Diagnosis
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on January 02, 2015
I had the same problem it was the isolator bolts. Here is a link that worked very easy fix. https://sites.google.com/site/fordf150p0171p0174fix/P0171P0174-Fix
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on January 03, 2015
Well I did what you said and wow it worked no more check engine light and it runs a lot better. I sure do thank you and so doz my truck. The parts ran about $75 and it took me about 4 hours thanks again.
on December 17, 2014
Turn on the truck and spray carb. cleaner on all air intake hoses. If you hear an RPM jump you have found an air intake leak. You call also try cleaning the MAF sensor and see if that helps. This vid may help as well : https://www.youtube.com/watch?v=qrao0Xj27Ss

I have seen where this issue presents with a failing COP.
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on December 18, 2014
Well I sprayed and nothing, the MAF has been replaced and cleaned, still has the same 2 codes. some times on the road I can put the peddle to the floor and she will take off and sometimes it will just go flat and nothing no power at all, but if I let up on it a little it will take off sometimes.
on January 06, 2015
Intake gasket is blown, my 4.2 did the same thing. The gasket was blown on the inside so a smoke test wouldn't pick it up. after 2 years of process of elimination, my boat mechanic told me what the problem was.
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on January 06, 2015
Thank you ill get back to you with my find thanks again. Well my gasket was blown too. There was a lot of oil in there too that I cleaned out. No more codes thank you very much and my truck runs great again.

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