High RPM During Driving After Service/maintenance
 

Hello friends. I drive Hyundai Matrix 1.6 2009 (petrol engine / automatic transmission). After changing 4 pieces of belts, timing belt tensioner, timing belt idler, 4 pieces of spark plugs, fuel filter and fuel pump filter (it looks like a white pillow) I see that car works in high RPM, it needs a long time to change transmission steps and I've got high fuel consumption now. Before maintenance, I rarely was seeing my car reaches 2000 RPM or high till 60 km/h. But now usually I need to get more than 2000 RPM for changing transmission steps.
Thank you for your time.

I cannot point to one particular thing that could cause this issue after your maintenance work. Maybe you could trace the steps you made. Hopefully you find an electrical connector that came apart or a vacuum hose.
It may be that the computer remains in warm up mode. Make sure the Engine Coolant Temperature sensor is working correctly.

Do you think it can relate to an electrical connector that came apart or a vacuum hose? I made car diagnostics 2 days ago and everything was ok.

Yes I think so. It takes awhile for codes to be set. The same error has to occur 2 times in sequence.

I just had another thought: did you disconnect the battery? If yes then the computer has to re-learn everything. Take it for a longer drive.

I will use battery disconnecting method, thank you.