P0094
System
Powertrain (Fuel/Air)
Scanner required
Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Fuel System Leak Detected — Small Leak

Understand P0094, common causes, and the right TOPDON scanner to diagnose it.

Small fuel leak detected during pressure decay test.

Common symptoms

  • Intermittent hard start
  • Fuel odor
  • Check engine light

Typical causes

  • Minor injector leak-off
  • Small weep at filter head
  • EVAP-style pressure test failure on fuel system

What scanner do you need?

Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Use live data and freeze frame to confirm the fault before replacing parts. ABS, SRS, and network U-codes usually require a full-system scanner.

Diagnostic tips

  • Record freeze frame data when the code first sets
  • Clear the code only after fixing the root cause
  • Check for related pending codes that point to a common issue
  • Verify battery voltage is above 12.4V before chasing sensor codes

Recommended TOPDON scanners

Frequently asked questions

Can I diagnose P0094 with a basic code reader?
P0094 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with P0094?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.