Power Lost

[NeMiZiS]

OK, i had my 2g n/t taken to a shop to put a new clutch in and replace the rear main seal,
the first time i picked it up from them it ran great , but no speedo. So i took it back they hooked up the speedo and it was all good, so i drive it home get home and see an oil puddle!
so i take it back again and they pressure washed my engine and told me my headgasket is blown! ok so i took it home did a compression test and i was around 200 on all cylinders, so i don't believe the head gasket is blown, but ever since i got it back from them (the last time)
i have no peak power like the power band is just gone! it just slowly gets up i put new plugs and msd wires on it and it helped some. but my main question is what happened to my car?... if the compression is good and i got no water in the oil and no oil in the water, do y'all think the head gasket is bad ?..
i read that pressure washing , will mess up some of the sensors?.. is this true?... if so which ones?.

thank you , Taylor

 

[Boo5t_Addict]

Pressure washing can also mess up your ignition system. I would check that first before anything. That and your MAS.

 

[NeMiZiS]

ok i know this sounds dumb, but what is the MAS and what does it do?..
i put new plugs and new wires all ready, if the coil pack is sparking then it should be ok, right?.