Replaced engine has 132-148 compression.new knock sensor and wire intake and plenum gaskets spark plugs wires cap rotor timing components water pump tps checks out good timings good. Has a rough idle at lower rpms runs ok at higher speeds 40 mph stalls sometimes at slow speeds has a 5 speed trany the engine light has't come on maybe pcv clogged egr valve stuck open or bad maf sensor any ideas what you think it might be?