P0442 on a 2013 Ram 1500

P0442 means the EVAP system could not hold pressure or vacuum during a leak test, but the leak is small.

Not your vehicle? See general P0442 info.

Most common causes on the 2013 Ram 1500

Ranked from 1,254 NHTSA owner complaints filed for this vehicle.

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1
Corroded fuel tank strap/frame mount letting the tank sag and stress EVAP lines or the filler neck
High severity
An extremely large, recurring cluster of complaints describes the front fuel-tank strap mount rusting through (the same failure recalled on 2009-2012 Ram 1500s but not extended to 2013); as the tank drops it can stretch, kink, or crack the attached EVAP vent lines and filler-neck seal.
Reported in 20 NHTSA complaints
Parts:fuel tank strap fuel tank mounting bracket
2
Faulty gas cap or cap seal triggering a 'check fuel cap' message
Medium severity
One owner reported a recurring 'check fuel cap' dashboard message and check-engine light with no other fault found -- classic small-leak gas cap symptom.
Reported in 1 NHTSA complaint
Parts:gas cap
3
Sticking fuel filler neck / ORVR valve breaking the fill seal
Medium severity
Owner described the fuel nozzle repeatedly sticking in the filler tube for 5-10 minutes, consistent with a binding filler-neck flapper/ORVR valve that can also fail to reseal properly.
Reported in 1 NHTSA complaint
Parts:fuel filler neck
4
Restricted EVAP vent path causing fuel-pump shutoff during fill-ups
Medium severity
Owner reported the fuel pump repeatedly clicking off while filling, taking 30-40 minutes to fuel -- a symptom of a blocked or malfunctioning EVAP vent path that can also leak once the blockage clears or the component itself fails.
Reported in 1 NHTSA complaint
Parts:EVAP vent valve EVAP canister
5
Cracked or perished EVAP purge/vent hose (general aging)
Medium severity
Standard small-leak source from heat and age-related hose cracking, independent of the tank-strap issue.
Common cause
Parts:EVAP hose/line
6
Failed EVAP purge valve
Medium severity
A purge valve that won't seal allows a small, steady leak the EVAP monitor detects.
Common cause
Parts:purge valve
7
Cracked charcoal canister
Medium severity
Hairline cracks in the canister housing are a common small-leak point.
Common cause
Parts:charcoal canister

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These causes are aggregated from NHTSA owner complaints and general repair knowledge — this is not a diagnosis. P0442 on your car still needs shop confirmation before any repair.

Common symptoms

Check engine light
Fuel smell near vehicle
Usually drives normally
Hard start after fueling in some cases

What to check before replacing parts

Tighten and inspect the gas cap

Look for: A cap that doesn't click to full tightness, has a visibly cracked or flattened seal, or is simply missing is the single most common cause of a small EVAP leak — rule it out first.

Smoke-test the EVAP system

Look for: Because this is a small leak, expect only a thin wisp of smoke or a faint hiss at one spot (a hose, seam, or valve) rather than an obvious cloud — look closely and take your time.

Check purge valve sealing

Look for: A purge valve that doesn't hold vacuum when commanded closed lets a small amount of air bleed through, which the system reads as a leak during its self-test.

Inspect hoses near the tank and engine bay

Look for: Look for small cracks, soft/collapsed spots, or a hose that has pulled loose slightly at a fitting — any of these can leak just enough to trip a small-leak code without an obvious fuel smell.

Verify vent valve operation

Look for: A vent valve that doesn't seal fully when commanded closed prevents the system from holding vacuum during its self-test, which reads as a small leak even with no physical leak in the hoses.

Rather have a pro handle it? Find a vetted local mechanic.

Matching symptoms

Check Engine Light