Pls I rely need help urgently, I changed the brain box( engine control unit) in my 1994 Camry recently and also worked on the exhaust(a few leakage). since the day the car left the garage, have been observing this thick black particles coming out from the exhaust. It's ready embarrassing and an afraid, is any thing wrong with the engine?

The particles are carbon soot

maybe because ur engine is still fresh
let it work like a month(if it doesnt knock by then)

Check and make sure ur 02 sensor is still connected and working. Make sure ur Mass air flow meter is still working as well.

fr3do: The particles are carbon soot

maybe because ur engine is still fresh
let it work like a month(if it doesnt knock by then)

fr3do....you are not helping me oooooh. carbon soot is different from a smoking engine. this engine wasn't smoking prior to this.

9icetoo: Check and make sure ur 02 sensor is still connected and working. Make sure ur Mass air flow meter is still working as well.

thanks nice...I will check that out.maybe those things were disconnected during the last time I took it to the garage. I really appreciate.