Not much power

Hi and thanks for using 2CarPros.

I have no idea the extent of the damage and to what portion of the vehicle, but anytime someone experiences a loss of power, I always question if the exhaust or catalytic converters are damaged, restricting flow, or damaged in some way. Have you checked and confirmed the system wasn't damaged in the accident? It isn't something people normally check.

Here is a link that shows how to check. Do this and let me know the results. If the converters weren't replaced, they could have been damaged in the accident and partially plugging the exhaust flow. Also, let me know if the check engine light is staying on,.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Let me know what you find,

Joe

There is no physical damage for exhaust pipe.
My car is Vitara Brezza.

Is there any chance for the injectors changed by repair shop by fault one?

What happens if injectors of one car is changed with injectors of another car?

Many things can happen because not all injectors are the same. It could get too little or too much fuel, run poorly, not run at all.

Inlet manifold was broken and it was glued entirely by fiber experts. Can it be a problem?

If there is a leak or something isn't true and not mounting properly, yes. However, that would cause an engine vacuum leak. Take a look through this link. Try what it suggests and see if you find a vacuum leak.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know

Joe