Had plugs done few weeks ago at APS as well as getting the red hose replaced as I had a boost leak and just had coil packs done at Audi as per the recall. But it misses on idle and judders though the revs do not rise and fall. Also misses when giving it some and feels like it's holding back.
Was thinking it might be the Throttle Body needs cleaning? I also hear a small whirring sometimes when the cat has been turned off for about 5 minutes.
Any suggestions much appreciated