A Peugeot came into us recently with the owner reporting that the engine had been running rough for a couple of weeks. It was losing power under load, the engine management light had been on for several days, and on a couple of occasions the car had briefly hesitated when pulling away from a standstill. The owner had been putting off getting it looked at, hoping it would settle on its own. It had not settled. It had got worse. We got it booked in, plugged into our diagnostic equipment and started working through exactly what was going on.
The Diagnostic Scan Pointed to a Misfiring Cylinder and a Fuel Delivery Problem
We connected the car to our diagnostic reader, which communicates directly with the engine control unit, the onboard computer that monitors everything happening inside the engine. The reader pulls stored fault codes that the car itself has logged, which gives us a precise starting point rather than guesswork. The codes showed a misfire on one cylinder and a fault with the fuel pressure sensor. A misfire means the fuel and air mixture in that cylinder is not igniting correctly, so the engine is effectively running on less than its full capacity. That is why the car felt sluggish and hesitated under load. With the fuel pressure sensor giving inaccurate readings, the engine management system could not regulate fuel delivery properly, which was compounding the misfire and causing the rough idle.
Leaving This Running Would Have Pulled the Catalytic Converter Into the Problem
A persistent misfire sends unburnt fuel through the exhaust system. That unburnt fuel reaches the catalytic converter, which is a component in the exhaust that processes harmful gases before they leave the vehicle. When raw fuel hits the catalytic converter repeatedly, it overheats it. A catalytic converter that has been damaged by a sustained misfire can cost anywhere from 300 pounds to over 600 pounds to replace on a Peugeot, depending on the model. The part the car actually needed at this point was significantly less than that. Running it further would have turned a straightforward engine repair into a much larger bill, and the car would have continued losing efficiency and performance in the meantime.
We Replaced the Faulty Sensor, Cleared the Codes and Road Tested the Car
We replaced the fuel pressure sensor with a quality replacement part, cleared the fault codes from the engine control unit and reset the system. We then ran the car on a road test to confirm the misfire had cleared and the engine was pulling cleanly through the rev range without hesitation. The engine management light did not return, idle was smooth, and power delivery under load was back to where it should be. We also carried out a visual inspection of the surrounding components while we were in there, checking that nothing else had been affected during the period the fault had been running.
Watch for These Signs on Your Own Car and Book In Before It Gets Costly
Engine faults rarely announce themselves loudly at the start. What usually happens is a small change you might notice but not act on, a slight roughness at idle, a hesitation when you accelerate, the engine management light coming on and staying on rather than flashing briefly and going off. A light that stays on means a fault is stored and active. A light that flashes while driving means a misfire is happening in real time and you should reduce your speed and get the car looked at promptly. If you are based in Walsall, Bloxwich, Aldridge, Willenhall or Brownhills and your car is giving you any of these signs, do not leave it and hope it resolves. Engine problems that sit tend to bring other parts into the fault, and the repair cost grows accordingly.
At Platinum Vehicle Services we carry out full engine diagnostics, engine repairs, servicing and MOT testing across the Walsall area. Whether your engine management light is on, your car feels down on power, or something just does not feel right, we will tell you exactly what we find and exactly what it will cost before we do anything. You can leave us a message any time, 24 hours a day, 7 days a week, on 07970901354 and someone from the team will get back to you as soon as possible. You can also find us and book in at platinumvehicleservices.co.uk.
