Peugeot 908 P1799 Engine Trouble Code
What is Peugeot 908 P1799?
Peugeot 908 P1799 code can indicate a faulty oxygen sensor, which may eventually damage the catalytic converter (repair cost: $2,000–$2,200). Professional diagnosis costs around $200–$210. Oxygen sensors are often straightforward to replace — check your owner's manual for location and instructions. This issue should be addressed promptly to prevent further damage.
P1799 on the Peugeot 908
A known issue on the Peugeot 908 is that aftermarket air filter upgrades can inadvertently trigger P1799. High-flow filters alter the intake resonance frequency, causing the MAP sensor to report pressure readings outside factory calibration.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Peugeot 908 |
| Brand: | Peugeot |
| Model: | 908 |
| Code: | P1799 |
P1799 Peugeot 908 Symptoms
Check Engine Light
Illuminated Peugeot 908 dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Peugeot 908
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Peugeot 908
Increased Emissions
Failed emissions test due to P1799
P1799 Code Structure
Understanding what each digit means in the P1799 powertrain trouble code:
| P | 1 | 7 | 9 | 9 |
|---|---|---|---|---|
| Powertrain Code | Fuel And Air Metering | Fuel Rail Pressure Sensor Circuit Malfunction | Crankshaft Position Sensor A Circuit Malfunction | Reverse Input Circuit |
How to Fix Peugeot 908 P1799
Diagnostic Steps:
Regarding P1799, carefully inspect the wire harness near the intake manifold bracket, best accessed from below near the oil filter. Look for chafing, pinching, or damaged insulation.
Repair Solution:
Regular maintenance of indicator and headlight bulbs ensures proper function. Maintain paint condition to prevent rust. Modern products make these maintenance tasks straightforward and accessible.
Technical Notes:
P1799 DTC indicating a sensor fault does not always mean the sensor itself is bad. The issue may stem from the systems being monitored or even the sensor wiring. Proper diagnosis is essential.
Peugeot 908 P1799 Repair Cost
Fuel injector cleaning service on the Peugeot 908 costs $150–$300 for an ultrasonic bench-clean of all injectors with flow-test certification. On-car induction cleaning is a cheaper ($80–$120) first step but is less thorough for heavily fouled injectors.
P1799 Description
P1799 engine trouble code is related to Reverse Input Circuit.
Main Cause
The primary reason for P1799 OBD-II Engine Trouble Code is: Fuel Rail Pressure Sensor Circuit Malfunction.
Common P1799 Misdiagnosis on the Peugeot 908
On the Peugeot 908, the EGR cooler is sometimes replaced for P1799 when the EGR valve position sensor is at fault. The two components share a fault pathway in older scan tools that do not display live EGR valve position data.
DIY Repair Guide: P1799 on Peugeot 908
The throttle body on the Peugeot 908 can be cleaned without full removal. Use a clean rag and throttle body cleaner spray with the engine off and cool. After cleaning, an idle relearn is mandatory: disconnect the battery for 10 minutes, reconnect, and allow the engine to idle for 10 minutes undisturbed.
Preventing P1799 on the Peugeot 908
Using only genuine or OEM-specification fuel injectors in the Peugeot 908 ensures precise spray pattern and flow rate. Inferior aftermarket injectors are a documented trigger for P1799 through off-target fuel delivery.
Frequently Asked Questions — Peugeot 908 P1799
A: Yes. Any stored fault code — including P1799 — will cause an automatic failure in most OBD-II based emissions tests. The code must be resolved and the vehicle must complete a full OBD drive cycle with no new codes before the test.