I have a Toyota Corolla. The check engine light came on and the car does not accelerate. It starts, but it won't go faster than 5 mph.
Is it a Manual Transmission or an Automatic? First you should check to see if your brakes are not locked up. When you turn the car on and press the brake is it really hard to get the pedal to go down? If your pedal goes all the way down and you get a whaut sound when releasing the brake pedal? You could have a bad Power Brake Booster which could cause your brake pistons to close but will not allow them to retract thus causing you to accelerate more to pickup speed because the rotors are heating up and swelling against your already locked brake pads & pistons. if you have a Manual transmission your problem could be A worn Clutch. If it is an Automatic Transmission your problem could be your transmission torque converter. There is no true diagnosis here without an on sight inspection of the vehicle. I urge you to watch some videos on the subjects I mentioned here. A good idea is to purchase a cheap $50. vehicle scanner at your local Auto Parts Store. I keep one in my car incase anything goes wrong I can plug it into my vehicle wherever I'm at and just use my phone to Google the scanner codes for their definitions which will tell me what's wrong with the car. This is how I help Friends, neighbors, and drivers on the road. The cheap scanners will only give you the code but the more expensive scanners can go as far as telling you what part you need to replace