Sometimes car runs good

I have a 2005 mustang gt 5speed that ive had some issues with performance wise! My idle when taking of in first gear woukd drop almost like if the the car wanted to die and ive cleaned the throttle body and maf which kinda helped a bit but the car someone ends up running very sluggish very bad throttle response ect and even affects the shifting.. Well about two weeks ago i thought maybe the drop in K and N filter might have something to do with it and i replaced it with a stock filter cleaned the throttle body and sprayed the crap out of the maf didnt bother resetting computer just to see if theres a difference and let me tell you ive never felt the car run so amazing! I was very happy and the response was there the shifting was crisp for some reason i mean it was a different car. After about two weeks its started to i guess fade?? Alnost like its slowly going back to how it was?? No check engine light nothing! Today the car felt sluggish almost how it delt before i just cant understand whats going on. It ran like a dream for about two weeks and now its back to how it was? Please help! Ive replaced the spark plugs a few months ago, fuel filter 93k miles any help would be greatly appreciated!!

No codes i wish the part would just fail and throw a code cus im getting fed up.. Spmetimes i wonder if its just the adaptive learning but it just doesnt make sense how cleaning the maf and throttle body putting stock filter back make such a difference but over the course of a week or two just feel so bad.. Today on my way home from work it felt like it was underpowered nothing like how it felt a couple weeks ago. On the freeway in 5 gear i got annoyed and just smashed the pedal to the floor literally and almost absolutely nothing happen. Clutch is not slipping the rpms didnt even move much..

I actually replaced the TPS sensor cus i thought thats what my problem was 3 months ago and it didnt make a difference is that what u meant by electronics in the TB?

I actually was gonna buy a used one from someone and he was willing to let me try it out before hand. I replaced the stock tps with a motorcraft one but didnt notice a difference. I did the throttle reset/ recalibration procedure that many have talked about with key on position pressing pedal in and repeating couple times ect and it actually helps out the throttle it seems. But it eventually goes sluggish. Its very inconsistent.. Specially when its really bad it feels like the car wants to stall when engaging the clutch rpms drop and it even affects the shifting ones in gear. My car is bone stock and sometimes i wonder if its cus it probably needs a tune but the only reason why i havent modded the car because i want it sorted out before i do any of the stuff... Is it the adaptive learning crap im experiencing or is it something else affevting drivability?