Acceleration issues going uphill?

2011 HYUNDAI SONATA

153,000 MILES • 2.4L • 4WD • AUTOMATIC

KLSRED

MEMBER
2 POSTS

I have acceleration issues mostly going uphill for about two weeks now. I had my spark plugs replaced about a week ago. The other day i was on the highway and it was stalling. I exited off at a stoplight and it idled loud then went back down. I drove to the next stoplight and the car cut off and all the lights came on in the dashboard. I crank it back up and went home. Had the alternator tested and it was bad. I had it replaced a few days ago but still runs the same

Sep 6, 2026 at 12:41 PM

STRAILER

✓Experienced Mechanic
55,381 POSTS

I would service the throttle body first, also are there any codes stored? Here is a video to help you get the codes and a guide to help you service the throttle body with a image below as well.

https://www.youtube.com/watch?v=LBCpCWEFnTg

and

https://2carpros.com/articles/throttle-actuator-service/

Please let me know what happens.

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Sep 7, 2026 at 9:44 AM

KLSRED

MEMBER
2 POSTS

Yes I got a code p0106 which pointed to the MAP sensor. I had that replaced today and the rough idling stopped. The car no longer cuts off but it is still slowly accelerating on highways especially on incline.

Sep 7, 2026 at 10:20 PM

STRAILER

✓Experienced Mechanic
55,381 POSTS

Yes, this can be the clogged catalytic converter. Here is a video and a guide to help us find out why you still have low engine power.

https://www.youtube.com/watch?v=kNXh1Lphzr4

and the guide

https://2carpros.com/articles/engine-has-low-power-output/

Please go over these and get back to me.

Sep 8, 2026 at 9:23 AM

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