Question 1

What does P1399 mean?

Accepted Answer

P1399 - Random Misfire (Honda). Honda-specific random/multiple cylinder misfire code.

Question 2

What are the symptoms of P1399?

Accepted Answer

Check engine light, Rough idle, Hesitation, Loss of power

Question 3

What causes P1399?

Accepted Answer

Worn spark plugs, Distributor cap/rotor (older Honda), Valve adjustment needed, Low fuel pressure, Vacuum leak

Question 4

How much does it cost to fix P1399?

Accepted Answer

Typical repair cost: $20-$800. Honda uses P1399 for random misfires instead of the generic P0300 on some models. Honda engines are sensitive to valve lash — valve adjustment every 30K miles is recommended.

P1399 — Random Misfire (Honda)

Don't guess — diagnose P1399 the right way

Common symptoms of P1399

Common causes of P1399

Repair cost & difficulty

Vehicles commonly affected

Related trouble codes