First, this vehicle isn't offered in the US, but I will try my best to help.
If you are hearing a pop in the exhaust, it sounds like it is an ignition related issue. I say ignition because of the water you mentioned.
How much water did you go through? Did the vehicle stall when in the water?
Here is a link that explains how to fix a back fire. I'm adding it, but I suspect we will need to go deeper into the issue.
Let me know. Also, if you could possibly record the engine cranking and upload it for me to hear, it may help.
Wednesday, October 7th, 2020 AT 6:31 PM