Engine loses power for a second then regains full power

The first thing you need to do is have the system scanned for fault codes, That is the start of the repair process. Best to take it to the dealer.

how many km /miles on the engine

cylinder compression / valves /02 sensors/ engine ECU
injectors/ fuel filter/ fuel pump
spark /coil packs

What OBD Codes do you have
& why would you use it, with any problem,
especially a known systems malfunction,
that give you a dash light

check for a lose wire in the fuse box or a bad conection

all gears ok but drive, full power from engine to tires, 1,2,R
right? but not drive. drives acts as Neutral or weak.
did you do the stall test , in drive.
1000 rpm weak, engine
2000 rpm good
over that much is tranny slip.
tranny issues.
read the fsm. then the on car service, section

my had same probiem i clean fuel filter know it,s ok you do the same and se how he goes

Sounds like a faulty boost pressure sensor or waste gate. I would check the waste gate first. Sounds like it is opening to soon and letting the boost out, than regaining again.

Mass air flow sensor or map sensor? Is the check engine light on? if so what code is it setting?

How did you check the battery? This needs to be done with a load test to be sure. Most car parts places will do this free. Battery leads OK? Not corroded? Also have the altenator checked for proper voltage out.

1st thing to do is have the system tested for the code that caused the check engine light to come, you may also have a fuel pump starting to fail or many other things, the check engine light may be the key. How many wiles on the car?