Hi guys, me again...Miggy has developed severe coolant leak, there was a leak from I don't know where but wasn't that bad. Almost 1l of coolant missing after a 100 miles, missfire from cold start (I wanted to believe it was faulty coil pack but I'm not so sure now), got 0340 code 2 times but that happened after I removed cambelt cover to see it there's water pump leaking ( and it is leaking, but it seems not so bad), so maybe it was me fiddling around cam sensor that day. No other code stored or appeared while this missfire is happening. Also there is really strange smell coming out of the exhaust, like something is added to gas fumes and it's smoking all the time, even when engine temp is up to normal. I've been reading a post of a member here few days back and his miggy had similar symptoms leading to head gasket change. Can anyone help me out with this? I'm really confused now

Thanks in advance guys