OBD-II Code
P1167
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$180–$1,400
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
$180 (PCV elbow + intake gaskets DIY) to $1,400 (intake manifold replacement + gaskets on a 5.4L 3V with shop labor).
P1167 in the Ford definition is a fuel-trim lean code on bank 1 that escalates beyond the generic P0171 — the PCM has corrected long-term fuel trim past roughly +25% and held it there long enough to trigger this stricter Ford-specific lean threshold.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP1167 in the Ford definition is a fuel-trim lean code on bank 1 that escalates beyond the generic P0171 — the PCM has corrected long-term fuel trim p…
P1167 in the Ford definition is a fuel-trim lean code on bank 1 that escalates beyond the generic P0171 — the PCM has corrected long-term fuel trim past roughly +25% and held it there long enough to trigger this stricter Ford-specific lean threshold.
The cheapest-first diagnostic ladder is the same as a P0171 with a sharper edge
- Smoke-test the intake — sustained LTFT north of +20% on a Ford is 80% of the time a torn intake-manifold gasket, a cracked PCV hose, or a brittle vacuum tee. Cap the throttle body and pump 0.5 psi of smoke; anything visible at the PCV port, the brake booster line, or the IMRC/IMT actuator vacuum lines is the leak.
- Check MAF g/sec at idle — Ford 4.6/5.4L should see 5-8 g/sec at warm idle, EcoBoost 3.5L should see 3-5 g/sec at idle and climb proportionally with rpm; under-reporting MAF starves fuel and creates a false lean signal.
- Dead-head a fuel-pressure gauge on the rail — port-injected Fords spec 55-65 psi at idle, EcoBoost direct-injection low-side spec 50-65 psi with HPFP-side commanded as needed; below spec means weak FPDM/pump or restricted filter sock. Don't condemn the long-block for a stuck-open EGR or a leaking fuel-injector seal until you've read keep-alive memory for an unauthorized-tune flag — aftermarket tunes that disable the rear-bank O2 monitor or rescale the MAF transfer function can mimic a hardware lean condition and waste hours of misdiagnosis.
Vehicle-specific patterns2004-2010 Ford F-150 / Expedition 5.4L 3V Triton is the canonical P1167 victim — the plastic intake-manifold gasket at the rear cylinders cracks arou…
- 2004-2010Ford F-150 / Expedition 5.4L 3V Triton is the canonical P1167 victim — the plastic intake-manifold gasket at the rear cylinders cracks around 80-120k miles and pulls a localized vacuum leak that pegs bank 1 lean; Ford issued multiple TSBs and the updated composite manifold gasket is the fix.
- 2007-2010Ford Edge / Lincoln MKX 3.5L Duratec throws P1167 from a cracked plastic intake manifold at the runner-to-plenum joint.
- 2011-2016Ford F-150 EcoBoost 3.5L commonly throws P1167 from intake-valve carbon (no port-injection wash) starving cylinders 1 and 4 of air-fuel mix homogeneity; walnut-blast service is the fix.
- 2008-2011Ford Focus 2.0L Duratec throws P1167 from a brittle PCV elbow that cracks at the valve cover.
Estimated repair$180 (PCV elbow + intake gaskets DIY) to $1,400 (intake manifold replacement + gaskets on a 5.4L 3V with shop labor).
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