What is the cause of the P1337 fault indicating misfire in cylinder 1 of the Peugeot?
4 Answers
The cause of the P1337 fault indicating misfire in cylinder 1 of the Peugeot is the failure of the spark plug and ignition coil. Below is the relevant introduction of Peugeot: 1. In terms of power: Peugeot is equipped with a 1.6T and 1.8T L four-cylinder turbocharged engine. Among them, the 1.6T has a maximum power of 170 horsepower, a maximum power of 125KW, and a maximum torque of 250 N·m, matched with an Aisin 6-speed automatic manual transmission. 2. In terms of interior: It tends to be youthful and fashionable. The new car adopts the Cockpit cabin design, featuring a compact two-spoke racing steering wheel, a standard 12.3-inch LCD dashboard elevated above the center console, and an 8 to 10-inch center control screen inclined towards the driver's side.
I'm all too familiar with this P1337 trouble code—just last week I helped a neighbor deal with the same issue on their Peugeot 307. Misfires in cylinder 1 most commonly stem from spark plug problems, like excessive electrode gap or cracked ceramic insulators. French cars in particular tend to use special long-thread spark plugs that are prone to issues. Aging ignition coils can also cause insufficient ignition voltage, especially noticeable in humid weather. Then there's clogged or poorly atomizing fuel injectors, which often come with a sudden increase in fuel consumption. If the mileage exceeds 100,000 km, you should also suspect valve seal issues—I've encountered cases where carbon buildup jammed the intake valves. The trickiest are circuit problems like distorted crankshaft position sensor signals, which require an oscilloscope for accurate diagnosis. I recommend checking the freeze frame data first to see at what RPM range the misfire occurs—this can narrow down the troubleshooting scope.
When I drove my old Peugeot 308 and encountered the P1337 fault, I was really anxious. Misfire in cylinder 1 first brings the ignition system to mind: if inferior spark plugs were used or they haven't been replaced for over 60,000 kilometers, they can easily fail, and oxidized ignition coil connectors can also cause poor contact. The fuel system needs checking too, as clogged fuel injectors or insufficient fuel pressure might starve cylinder 1. Once, I even found that the cylinder wire had been gnawed by a mouse, causing leakage. On the mechanical side, low cylinder pressure is a concern—valve erosion or piston ring wear can reduce compression ratio. For sensors, besides the crankshaft position sensor, abnormal intake pressure data can also trick the ECU. It's best to even check the engine mount rubber pads, as excessive vibration can affect combustion too.
Over the years in auto repair, I've seen many P1337 cases. The core of cylinder 1 misfire boils down to three elements: issues with spark, fuel, or air. A spark plug gap exceeding 1.1mm is dangerous, and ignition coil primary resistance over 0.8 ohms requires replacement. Clogged fuel injectors cause abnormal spray cone angles, and stethoscopes can detect operational abnormalities. Mechanically, cylinder pressure should be tested - below 9bar warrants inspection of valve guides. The most common wiring issue is ECU connector corrosion at pin 34 due to water ingress. An easily overlooked point is air-fuel ratio sensor drift, which can mislead fuel trim values. Finally, remember to check exhaust backpressure, as clogged catalytic converters can trigger chain reactions.
