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still have a lean code and having issues with engine 2003 Mustang GT

971 Views 9 Replies 6 Participants Last post by  Bullitt5339, 
jcalvin1126
I posted on here awhile ago about a lean ode I was having. Now I'm still having the issue and it's worrying me.. Heres the story.. I put on a set of bbk long tube headers with a catted h pipe.. Well I removed the cats and the engine started to throw a lean code. Mind you it's itermitten and not constant. Well I am changing the long tubes tomorrow and seeing if that fixes the problem. Anyway I took it to the ford dealership to get a diagnostic and with no luck.. The are saying that everything 02 sensor to egr are working fine and the ford factory is saying I need to switch to oem ford gaskets for the long tubes .. Well they ruled that out because I have that on it anyway haha.. So I got a tune from american muscle with the sct chip... Still nothing.. Now the engine is starting to die when I press the clutch in occasionally and runs ruff as if miss firing at lower rpms. But when I give it gas it smooths out.. Sooooooo my question is please will someone help.. I don't know what else to check.. Should I start replacing the fuel pump to the injectors.. Should I check my sparkp plugs.. Or what.. I'm lost now..
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hotshot
if it started right after your LT and mid-pipe i'd stick with things that are related directly to those
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jcalvin1126
well... I changed the headers out with no luck still having a stumbeling engine.. Uugh I'm debating on just swaping the motor out it's ticking me off

well I've been doing a lot of research. I found that the egr can cause these type of trouble and uppon further investigation I noticed that my engine only does this when I have a warm engine and i m at idle or low gas input. When I floor it it smooths out and I gues sthe egr shuts off at over 50 % throttle input thus I'm making a egr delete kit an hoping for the best .. Any inputs on this thought?
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G
what kinda plenum do you have?
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MeanChad1
04GTYellowStang said:
what kinda plenum do you have?
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He has a picture of a car on his profile and it is stock.
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G
oh okay, i was just wandering because i bolted back on my stock plenum and it got rid of my p0174.. i put back on the bbk 78mm and now it's back. even with a fatter tune from bama.

Ford P0171 & P0174 Lean Codes

i read that article.. im gonna check my egr... what's your opinion?


ps. sorry for hijacking, but this may also help you.
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W
have you replaced the upstream o2 sensors?
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jcalvin1126
ALLRIGHT!!! heres the update. I made a custom EGR plate to block the EGR valve ripped that sucker out (not literlly) and WALLLAAA its gone.. my engine runs as smooth as a baby's bottom. No lean code no stutter no nothing. Now all i have to do is tune my car to forget about the EGR valve.

(things

i did replace the 02 sensors clean the IAC and replace the headers and all kinds of stuff and this is the only thing that worked for me.. by the way if anybody wants one of those plates ill sell em to ya fo 2 buck plus shipping.
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S
Had similar issues as you described but ended up being a fly in my Mass Air Flow sensor. Getting lean codes. Checked vacuum leaks, EGR. Ignored O2 sensor since I've heard it rarely causes problems but gets changed out. Ended up pulling MAF sensor and, with magnification, found a tiny fly stuck on the wires inside the MAF. Must have gotten on the clean side of the filter when I checked 2 days prior. Lightly blew out (in reverse) and out came the fly. Reinstalled MAF and all seems well now.

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Bullitt5339
steveokc said:
Had similar issues as you described but ended up being a fly in my Mass Air Flow sensor. Getting lean codes. Checked vacuum leaks, EGR. Ignored O2 sensor since I've heard it rarely causes problems but gets changed out. Ended up pulling MAF sensor and, with magnification, found a tiny fly stuck on the wires inside the MAF. Must have gotten on the clean side of the filter when I checked 2 days prior. Lightly blew out (in reverse) and out came the fly. Reinstalled MAF and all seems well now.
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Man, what are the odds of that happening? When I first started reading, I was like "Well, what do expect with no air filter", which is what I assumed since a fly got in there until I kept reading......

Pretty funny, thanks for sharing that.
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