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Q: When you slow down then re-accelerate..sounds like severe downshift.

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When I slow down then re=accelerate, very easily, it's like the car downshifts from 6th to 1st gear. This is a 300hp engine. I accelerate as though I am in a 1985 Chevette automatic, yet it slams down as though I went to WOT, in a Corvette?

I am a 52 year old male, and I normally drive this car like an old lady. I rarely push this car, though it is very powerful. I bought Jan. 2015 used, and have no idea who drove it before me.

I suspect Transmission, Torque Converter lock-Up, or possibly CV joint (Inner). Any Thoughts?

This is a sudden acceleration that some fly by wire vehicles have been suffering from. Think of the Toyota Prius. Your throttle is electronically controlled and the PCM (Powertrain Control Module) takes a position reading from your foot pedal to know what you intend for your car to do. Unfortunately this system creates the possibility for problems such as you are having. Your transmission is also electronically controlled. In short, for some reason your car believes you want it to accelerate like your driving a Corvette.

You need to have your car diagnosed by an experienced technician. It will require an advanced level scan tool and a technician with experience with throttle control systems. This sounds like it is intermittent, so be prepared to give your technician extra time to figure this out. Intermittent problems can be difficult to recreate, making diagnosis very difficult.

In addition, this isn’t likely caused from how you drive your car. Failures happen just like a light bulb burns out. It just does when it is its time. Hopefully there is a Check Engine Light that indicates there is a code stored. This will often contain freeze frame data that can be used to understand what is occurring.

I recommend having your car looked by a qualified technician, such as one from YourMechanic, who can diagnose your car with a scanner to pinpoint the issue and help you fix it accordingly.

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