P2073: Manifold Absolute Pressure/Mass Air Flow — Throttle Position Correlation at Idle
What to do
Idle-only symptoms with this code — hunting, stalling at junctions, a high or uneven idle — say vacuum leak before they say sensor. A smoke test of the intake finds it in minutes and costs less than any of the three sensors this code could otherwise blame.
What this code means
The pressure and airflow readings do not agree with the throttle's position at idle — the condition-qualified version of P0068, and the qualification is the diagnosis, exactly as the corpus's lean family argues at P2177.
At idle, the throttle is nearly shut, so unmetered air is at its most visible. A vacuum leak that vanishes into the airflow at speed is a large fraction of the tiny idle flow — so a correlation fault only at idle points hard at leaks: a split hose, a leaking manifold gasket, a stuck purge valve bleeding the tank into the manifold. The same disagreement at load (P2074) points somewhere else entirely, which is why the standard splits the code.
The sensors themselves — pressure, airflow, throttle position — can each lie, but three of them cross-checked at the condition where leaks shout loudest makes the leak the first suspect, and a smoke test the cheapest decisive step.
Likely causes
Start here
- Vacuum leak in intake manifold or hoses · easy
- Leaking intake manifold gasket · moderate
Less common
Symptoms
Components involved
Information, not instruction
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Community experience
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