When pressing on the gas pedal, it needs to go a quarter down before responding. When the Check Engine light comes on, the truck will start as it should for a few days. And then it goes into Reduced Power Stabilitrak mode. I removed and reattached the battery cable, and then it works fine for a week or two.
The throttle pedal sensor and the throttle body sensor need to correlate to each other or the computer goes into limp mode and will not accelerate properly. A test to move the throttle body and throttle pedal position needs to be done to verify which one is the cause of the problem. You stated you replaced the TPS and gas pedal but did not mention the throttle body assembly. I expect the throttle body to be your problem but this will need to be verified. I recommend you have a mechanic like one from YourMechanic inspect your vehicle’s gas pedal for you.
Have a car question? Get free advice from our top-rated mechanics.