P1450 Excessive Vacuum

Code: P1450
Applies To: Ford
Loose Cap Can Set It: No
Diagnosis: $61 to $90 at RepairPal

Ford's code for too much vacuum in the fuel vapor system during its leak test.
A shop confirms it with the carmaker's EVAP test and a smoke machine before replacing parts.
Usually yes for now, but get it fixed soon and check for open recalls.

What The Carmakers Call It

excessive vacuum, as printed by Ford Motor Company

Causes Named In Carmaker Bulletins

Kinked vapor lines or a stuck open purge valve (source)
A purge valve that leaks but is not fully stuck open (source)
An open power input circuit or a stuck check valve at the tank pressure sensor (source)
A stuck purge valve on 2012 to 2018 Focus 2.0L, which can also deform the tank (source)

No source ranks these by how often they happen, so they are listed as the bulletins give them.

Ford lists P1450 for too much vacuum, the opposite of a leak.

What The Fix Costs

The usual part for this code is the smoke test and diagnosis. Published estimates put it at $61 to $90 at RepairPal. The full table with every source and date is on the cost page. A diagnosis first keeps you from paying for a part you did not need, which is why we price check engine light and smog check before the fix.

Getting The Light To Go Off

After the repair the light goes off once the EVAP test runs and passes on three drive cycles in a row, and the code is erased after 40 warm up cycles, per CARB. The test only runs under set conditions such as a fuel level between about 15 and 85 percent, so it can take days.

P0442Evap Emission Control System Small Leak Detected P0456Evap System Very Small Leak P0440Evap Emission Control System Malfunction