Acelarates and disalarates

Hello. It seems either the torque converter; if your vehicle has an automatic transmission or clutch; if your vehicle has a manual transmission are defective/malfunctioning. Torque converters and/clutches will cause 'jerking' while driving and 'stalling' the engine when slowing/stopping the vehicle because they won't engage/disengage like they are supposed to. Good luck and keep me informed; if you want to.

would be your water pump going out, do you have overheat problem in freeway? if you do, you water pump is going out.

Clutch is worn out or alternator generator is going bad. Take it to a tune up shop for proper diagnostic

All that work! Seems to me your problem may simply be the Throttle Position Sensor (TPS).
Have someone (an electrician) bench test it FIRST!... If the TPS (its a potentiometer) has bad spots in it, it CAN and WILL cause hesitation.

Take it to the dealer, they have the means to figure it out, we had one like that , the problem was the skid control module. I drove the vehicle for two days I did not believe the customer until that happen to me, I went to the store and the car was braking by itself, the techstream computer was attached to the car and record the events, the abs computer ( skid control ecu ) allow hydroulic pressure enter the master cylinder thus braking the car. the replacemant of the solule was this modution.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/flavio_517b938f50183b92

Driving down several hills today and my car decelarated. It would not coast. I had to use gas going down. This happened yesterday as well. Today, the check engine light came on

It could be a bad sensor or bad instrument cluster or wiring?? Hard to tell without more information

play in the cv axles loose tranny mount loose engine mount just to name a few.

possible clogged catalytic convertor

could be a vaccum leak, any work prior to the incident, or just really old hoses could be a problem, i change my vaccum hoses every 2 years