get a decent boost gauge mate.. and i dont think you have an egt probe mate.. the top one is your lambda/ 02 sensor which determins your air fuel ratio.. if this is damaged your fueling could be all over the place.. smoke/ vapour indicating its running rich... on another note the bottom sensor is a cat temp sensor so having a decat i very much doubt that this is inserted.. so just to confirm.. you have decat, stainless mani but still standard exhaust?