Peugeot 208 pure tech fault code P1337 keeping coming back

[Namnam]

Hi everyone! I’m battling a stubborn issue with my **Peugeot 208 1.2L PureTech 2019 and could use your collective wisdom. Here’s the breakdown:

**Symptoms:**
- Engine fault warning + **limp mode** (recurring after 10 miles of driving).
- **Fault codes**: `P1337` (persistent)
- Cooling fan runs continuously *even after engine is off*.

**What I’ve done so far:**
1. Replaced coil pack + spark plugs → Fault cleared temporarily but returned.
2. Changed fuel injector → No luck.
3. Replaced crankshaft sensor → Fault persists.
4. Checked compression:
- Cyl 1: **137 psi** | Cyl 2: **135 psi** | Cyl 3: **135 psi** (all within spec).

**Questions for all **
1. **Has anyone solved recurring P1337 on the 1.2L PureTech?** This code keeps haunting me!

- Fault returns after ~10 miles of driving.
- No visible wiring damage.

Huge thanks in advance—this one’s got me stumped!

[xantia_v6]

Did you consider that a new coil or spark plug may be faulty?

[Namnam]

Hi ,
1. **Initial Fix:** Replaced the faulty coil pack from previous engine . The car ran well for a few days before returning to limp mode.
2. **Second Attempt:** Installed another coil pack from a previous engine. The P1337 code resurfaced.
3. **Swapped Components:**
- Swapped the coil from Cylinder 1 to 2 also spark plugs
Issue recurred shortly after.
4. **Injector Replacement:** Replaced the injector (also from a previous engine). The P1337 fault still persists.

[Namnam]

Dear xantia_v6

I am writing to seek your expertise regarding my [Peugeot 208 1.2l pure tech ], which has been experiencing persistent breakdowns. The issue is accompanied by the fault code P1337, which I have been forced to clear using my code reader in order to drive the vehicle home.

Recently, I had the opportunity to borrow an X431 Pro diagnostic tool, but unfortunately, it did not reveal the cause of the P1337 code. However, it did uncover other issues, including:

• Fault code U1318: Communication with the BSI (Body Control Module) - Data Received Invalid
• Live data streams showing:
○ Upstream Oxygen Sensor Voltage: 0V
○ Downstream Oxygen Sensor Voltage: 0V
○ Engine Coolant Temperature: 90°C

I have taken a screenshot of the live data readings and would be happy to send it to you for further analysis.

I would greatly appreciate your assistance in diagnosing and resolving the underlying issue causing these problems. Please let me know if you require any additional information