engine randomly starts running very sluggish usually after warmedup
even full throttle it still runs very bad like its getting no power but after the revs slowly build up it sounds much better
the sluggish response comes and goes often
i suspect headgasket ,timing problem, blocked exhaust

also been getting alot of foam/moisture under cap ive never had before, oil is clean with no foam
could moisture from not having PCV or onewayvalves cause this?

i thank anyone who could give me some advice or answers