Hi I'm having a problem with my petrol zetecs s 58 plate where when I'm driving the car normally it will all of a sudden loss power even when my foot is half way to the floor and feel like it breaking so I take it out of gear give it a rev then it's back to normal. I changed my spark plugs and air filter but it seems to be getting worse, I was wondering could it be either the coil pack or leads or the MAF sensor. I also got told it could be the fuel filter getting blocked. Also the average speed reader on the trip meter doesn't work
If your vehicle is losing power, I would recommend having an engine diagnostic performed by a qualified mechanic. This inspection would run several tests including a scan of your vehicle for trouble codes and going from there depending on what codes may have been stored in your vehicle’s PCM (powertrain control module). If the problem happens all the time, it is possible that you may have an ignition coil or MAF sensor issue.
If the problem happens intermittently, you may have a fuel issue such as a fuel pump going bad or a clogged fuel filter just like you suggested. Since it is likely that you have a trouble code stored due to this issue, the code(s) will give a better indication of which system of your vehicle is causing this loss of power issue you are having.
I also want to mention that if you said it feels like the vehicle is braking while you are driving it, I would recommend having your brakes inspected as well. Sometimes your brake calipers can get stuck causing them to constantly be applying the brakes which can cause the vehicle to brake even when the brake pedal is not depressed. Finally, the average speed meter not working is likely unrelated to the loss of power issue you are having. I would recommend checking in your owners manual to see if there is a way to reset it. For a complete inspection of the car, consider having a professional, like one from YourMechanic, diagnose your car in order to have the correct repairs made.
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