so i have a 1991 volvo 740 turbo with say 195,etc mils on it i have been having problem lately with it i have lose of power you start it up it runs normal but when you get on the gas it back fires and misfires and has trouble getting up to high rpms inorder to get up to high rpms you can hit the gas rapdle and it will slowly began to gain rpms but it still runs rough im not for sure whats wrong with it tho i have noticed that i have smoke coming from the dipstick its ex gases coming from it what could this be since the not a fuel problem because it has a new fuel filter and new fuel pumps also has new spark plugs and wires has a new tp senor and i did a compresstion test all 4 cyc showed 150psi what is wrong with this engine i need to know because this is my means of tranption in a couple of weeks

 

You may have a clogged cat.