Check engine light is on and car is not accelerating
I have V6 Hyundai sonata 2001, currently ~143k miles. I drove it around 30k miles with regular maintenance and no issues at all and a month back I got the timing belt replaced at the local Hyundai dealer. Today morning while starting for office it refused to accelerate and max it went 20-25 mph, I also noticed the check engine light switched on. I have discussed with the service center and scheduled a check. Can someone suggest what could be the reason and also could it be possible that while timing belt replacement some of the parts were not properly/correctly fitted in. I also think it did start burning more gas for last one month. I welcome your responses/suggestions.