Lean condition

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Jul 22, 2025 | 07:17 PM

96ford5.0

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7th Gear

Joined: Jul 2025

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Lean condition

All right guys I need the 9th gen experts here my 96 5.0 has got a lean condition to cross the whole engine now I pulled this engine out of a 6 7 months ago to rebuild it I did injectors fuel pumps all that vacuum lines are gone through before putting back in. my scanner will show that sometimes bank one will read normal at about zero but 100% of the time bank two reads at 32.8% lean but bank one most of the time follows bank two I've gone through all the vacuum lines again went through the EGR map sensor pretty much anything a guy would do that been working on these for the last 8 years I am very very stumped I don't normally come here for help but I'm going to call this truck the mystery mobile when we get this fixed and no I don't suspect the intake to leak cuz this was all just recently replaced

Jul 22, 2025 | 07:51 PM

Prototypemech

Logistics Pro

Joined: Nov 2013

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From: Mojave, Ca

Your o2 sensors are probably picking up fresh air from an exhaust leak, bad EGR, or a malfunctioning smog pump system.
Can you hear any exhaust leaks on bank 2 side? What condition is your EGR and pipes in? After 30 years, they tend to crack at the exhaust manifold. Did you remove your smog pump system and not seal up the air injection ports.

Jul 22, 2025 | 08:37 PM

wwhite

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Joined: Aug 2014

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How well does it run?
Does it run hot?
What codes as the EEC set?
What scanner do you use, are you sure the scanner is accurate?

Jul 22, 2025 | 10:06 PM

96ford5.0

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7th Gear

Joined: Jul 2025

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Lean condition

Smog pumps been deleted long time ago unrelated at this point I've already been threw the EGR and as I mentioned motor was rebuilt about 7 months ago and no I don't suspect any exhaust leaks this early nor do I hear any and yes I have a decent scanner two of them actually in both of them say the same thing in the truck runs like a scalded dog literally no joke I have out ran newer trucks with this stock rebuild 5.0 it runs great going down the highway and when you put your foot in it and I get a little over 18 miles a gallon just the idle sucks and timing is in check I'm just getting a lean condition with idle only can't make sense of it

Jul 22, 2025 | 10:08 PM

96ford5.0

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7th Gear

Joined: Jul 2025

Posts: 7

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Lean condition

As for codes I don't know the specific ones on hand but it was for every O2 sensor in the truck all three of them in which I have a hard time believing all three of them just happened to be bad and as I've said in my original post bank one will occasionally run around zero give or take for the fuel trim bank 2 is dead at 32.8 Lean