Hi folks i have just removed both manifold cats on my 3.2 gsi due to a 0422 fault code (cat threshold to low) for £19 and solved the code issue.
basically after lots of research i found it possible to fool the after cat lambda sensors on the manifold by simply spacing them away from the exhaust flow using spark plug defoulers although i know this wouldnt solve the blocked cat issue so before paying silly money having tubular manifolds with sports cats made up i chiselled out the cats from the manifolds(the rear one was really blocked) in essence leaving a straight through manifold to see if any change was noticed and if the eml would stay off (wouldnt want to spend out and find out after that the eml stayed on).

The results are good the eml has stayed off for 900+ miles now and a vast improvement in mpg( avarage was 27mpg now 36mpg on the same daily run). Torque has also vastly improvedand it seems a lot more responsive all through the power band especially after 4k. it sounds a lot more meaty now and pops and bangs on lifting off from highish revs i have a std exhaust system with the other cat in the downpipes removed and the centre silencer also removed
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I am planning getting a custom set of tubular manifolds made up now with sports cats for mot time will keep you updated. anyone wanting the spacers for the lambdas i bought them from merlin motorsport but see mij exhausts have them also so may well approach them to do the mainifolds(any recommendations welcome) will try and post up a few pictures when the weather improves