Re: ITB Conversion on 16 valve 4AGE On my stock bigport AW11 a leaking exhaust manifold gasket brought about the O2 sensor to read through lean and it pumped gas in to the motor. Fuel economy plummeted until I sorted it out.I examine on the internet that when they are not nicely synced it might cause wealthy jogging, backfiring and vibrations. Perh… Read More