kyaloj

Any idea on what could be causing carbon fouling on one set of the plugs for the rx 350, 2010?

this happens in the front bank of the engine. I mean the three plugs on the front side.

fuel consumption is horrible. Black soot on the exhaust. Fuel smell at the exhaust when engine is running.

Mesquite77

You will need to get a scan tool and post short and long term fuel trims for both banks, but it looks like bank 2 (rad side) has an A/F mixture problem caused by a bad injector or a lean A/F sensor reading causing it to dump too much fuel into it, or some other problem causing poor combustion. Suspects: coils, A/F sensors, O2 sensor (unlikely), injectors. The thing is the whole bank mixture controlled by one set of sensors, so a problem in one of cylinders 2,4,6 will mess it up. Need scans...