there's a whole mess of pipes under the inlet manifold, for various systems (pcv, sai, evap) which are all prone to leaking. They could cause idle issues.. but shouldn't be causing your unresponsive right pedal symptoms.. thats why i reckon throttle body.
if you want it looked at properly, book in with r-tech and it might be something simple that i'll spot in 5 minutes, or if it's the throttle body i think we have a spare aum one in the workshop to try (or pinch the one off my car temporarily

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