Q: Car is struggling to go past 40 MPH.

asked by on November 30, 2016

Took to auto shop this morning and they ran a diagnostic for $70. They want do a 3 step fuel cleaning process, replace spark plug wires, and replace the mass airflow sensor for $590.

I can get the parts myself for about 170ish and i'm not convinced the 3 step fuel system is needed since ive had service on the fuel system about 8 months ago. (fuel pump went out)

I feel like i'm getting scammed here.

My car has 270000 miles.
My car has an automatic transmission.

Mass Airflow Sensor Replacement $171.84 - $740.29 Get a Quote
Spark Plugs Replacement $96.63 - $636.71 Get a Quote
Loss of power Inspection $79.99 - $89.99 Get a Quote

Hi there. If your vehicle is having trouble going past 40 mph, then check the mass air flow sensor (MAF) and the fuel pressure regular. Both of these items could be restricting the engine and causing it to have a loss of power. Shops will charge for what they find wrong with a vehicle to their knowledge, however, if you are able to do the work yourself, then that could save you a lot of time and money. Even though your engine had a fuel injection cleaning 8 months ago, if you were to get fuel from a slow fuel station (a place with few customers) then you could get the junk that is in the fuel and the junk could have gotten into the fuel rail causing a restriction. I recommend putting a can of sea foam in the fuel tank and also putting a can of sea foam in the vacuum system (tricked in) to clean the engine up and stabilize the fuel in the tank. If the engine continues to have a loss of power, then I recommend replacing the MAF and spark plugs. If you need further assistance with your engine loosing power, then seek out a professional, such as one from Your Mechanic, to help you.

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