Powertrain, generic (extended)

P2E58 Alternative Fuel Random/Multiple Cylinder Misfire Detected

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2E58 is the collective misfire code for running on the second fuel, mostly CNG or LPG: misfires are counted while gas is burned, but no single cylinder can be blamed, or several each carry a large share. CARB treats a bi-fuel car as alternate-fueled only while it runs on gas and asks for the same misfire monitor as on petrol; EPA likewise requires converters to keep OBD working on the conversion fuel. No carmaker documents P2E58 openly; Honda's Civic CNG and Roush propane trucks log gas-mode misfire with the ordinary P03xx codes. A GM patent checks both fuels: misfire on gas only points to the gas side, on both fuels to ignition. Likely culprits are an iced or poorly heated regulator or vaporiser, a clogged filter, low gas pressure or a lean mixture. One-cylinder faults are P2E59 to P2E60.

Likely causes

Gas pressure regulator or LPG vaporiser iced up or not heated enough (low coolant flow, moisture in the gas)
Too little gas pressure at the rail – clogged gas filter, nearly empty tank or weak regulator
Worn plugs or weak coils on several cylinders that cope with petrol but not with the harder-to-ignite gas mixture
Lean gas mixture from an intake air leak or wrong gas-system calibration

Symptoms

  • Rough running or jerking only while the engine runs on gas
  • Bi-fuel vehicle switches back to petrol on its own
  • Check engine light on or flashing, gas-mode indicator may flash

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–1,500
Time1–6 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

alt fuel injectorsalt fuel railignition coils

Related codes

P0300P2E61P2E59P2E60P0171P0174

References: law.cornell.edu, govinfo.gov, image-ppubs.uspto.gov, static.nhtsa.gov.