I want to buy a swapped b18c2 integra 92. It is getting 5km per liter. I don't know what's the problem. What might it be can anyone suggest me? I want to buy it really bad. The owner just want to get rid of it. If I guy it can I get milage UpTo at least 8 to 9 km/L on it. What should I do after buying it to fix the issues.