Citroën vehicle error code P1338: What does it mean and how to fix it?

Artigo voltado ao mercado Brasileiro. Artigo atualizado em 15 de May de 2026 por João Daniel

When the check engine light comes on in a Citroën and the engine starts to misfire, shake excessively at idle, or lose power during acceleration, the automotive scanner often points to the problem. DTC P1338. In the engineering department of the PSA Group (Citroën/Peugeot), this code is very specific: it indicates Severe Misfire in Cylinder 2 (or Misfire in cylinder 2).

This means that the electronic control unit (ECU) detected that the fuel injected into the second cylinder did not burn as it should. To protect the catalytic converter from damage caused by raw fuel in the exhaust, the control unit may even cut the pulse to the injector nozzle of that cylinder, causing the car to run “on three cylinders” and enter emergency mode.

The Main Symptoms of P1338

Identifying this code in everyday use is relatively simple due to the vehicle’s behavior:

• “Weak” and erratic engine: The car shakes a lot, reminiscent of the behavior of an old, poorly tuned engine.
• Message on the panel: Warnings such as “Engine fault: Repair the vehicle” appear on the on-board computer.
• “Clean Mode” effect: The car suddenly loses power on the road and limits its speed for mechanical protection.
• Electric fan triggered: It is common for the radiator fan to remain on at maximum speed for several minutes after the car is turned off, a strategy of the ECU to prevent overheating due to irregular combustion.

Solution: The Step-by-Step Guide to Effective Diagnosis

Many people make the mistake of randomly swapping parts when they see error code P1338. The correct approach is to follow a logical testing process focused on… Cylinder 2 (counted from right to left, i.e., from the gearbox to the belt in French engines):

1. Coil Reversal: The quickest test: Swap the coil from cylinder 2 with the one from cylinder 3. Clear the code and drive the car. If the error changes to P1339 (cylinder 3), the coil is burned out or has a current leak.
2. Examination of the Bougies (Sails): Remove the spark plug from cylinder 2. Check the electrode for wear and for the presence of carbon deposits or oil. Out-of-specification or worn spark plugs easily cause error code P1338.
3. Fuel Injector Nozzle: If the coils and spark plugs are okay, the injector for cylinder 2 may be stuck, leaking, or have altered resistance. A test with an injector testing machine will resolve the issue.
4. Attention to the Cylinder Head (Mechanical): If the problem persists after the electrical system check, perform a cylinder compression and flow test. In 1.6 EC5 and THP engines, valve sealing problems or excessive carbon buildup can cause persistent misfires.

Interesting fact: Counting Cylinders in Reverse

Did you know that the cylinder numbering in the Citroën line follows the… French standardThis is the opposite of most Asian and American brands. In most cars, Cylinder 1 is located on the belt side (front of the engine). In Citroën and Peugeot, Cylinder 1 is located on the flywheel side of the engine (next to the gearbox).. Therefore, if the scanner indicates P1338 pointing to cylinder 2, remember that it is the second cylinder counting from the transmission, not the accessory belt!