well mine had sticky stuff in the exhaust but it wasnt really gooey or anything just like normal soot but excessive ammounts and it was slightly tacky when u rubbed it between your fingers. i also didnt have any performance issues but it did get to the stage where i had to fill up with oil every time i filled up with fuel! all in all for a brand new bottom end from vw, have my head refurbed, new cambelt, service etc, labour and vat it came to just shy of £1600.