Car enthusiasts: If one fuel injector is broken, can I just replace that one, or do I need to replace all four?

I just bought a used 2009 Accent with 90,000 km on it. Do I need to replace the timing belt?

Is it better to repair the broken navigation touchscreen or just replace it with an Android one?

Will driving 5,000 kilometers without adding a cleaner clog the fuel injectors? Do you need to clean the turbo blades at 20,000 kilometers?

Hello, car enthusiasts group. When swapping the positions of all four tires, is it necessary to do wheel balancing and alignment?

The air conditioning internal circulation of the 2016 Hongqi H7 with the chrysanthemum logo is broken. How can it be repaired? Is it that one of the shafts of the air conditioning flap is broken? Do I have to replace the entire air conditioning assembly?

Do I need to replace both small batteries if one of them is dead? Please help, everyone.

I'm planning to change my tires. Does anyone have cheaper sources for Michelin? I need to replace all four. [Facepalm][Facepalm]

Car enthusiasts: If one fuel injector is broken, can I just replace that one, or do I need to replace all four?

How often should the timing belt be replaced? My car is over 9 years old with 81,000 kilometers on it. Do I need to replace the timing belt? Thanks to all the fellow car enthusiasts.

What should I be aware of when purchasing a 2021 model 5008 from existing stock? Do I need to replace all the fluids and the battery?