Hey all, i run my 4cyl honda vtec on premium fuel (as it should be). The premium here in australia is supposedly nothing compared to the overseas ones so i put some octane booster in my tank. It ran well the first tank yet i put a little bit more in the next time i filled up. After filling it the second time and adding the octane boost my car is running extremely rough. Conditions are - Idleing inconsistently and lots of engine movement - can feel it in the wheel! - Changed engine tempo, much deeper growl, sorta like a WRX with a 4 inch exhaust (and my car isnt a WRX) - Extremely slow in low revs and struggling to pull hard, same in higher revs - When the VTEC kicks in it sometimes clears up but other times its extremely laggy. - Sounds like the cars going to backfire...... well not really but it has that excess fuel build up sound in the exhaust like theres unburnt spits. Any ideas guys? i thought maybe the octane boost has clogged up my injectors yet im not too sure. Thanks