3.0tdi inlet manifolds conundrum

[Andy JB]

So my A6 Allroad 3.0 TDI has developed the well documented issue with manifold inlets via the engine warning light.

Diagnostics showed -
4120 intake manifold runner bank 2 and
12597 intake manifold runner control

So I replaced via local indy both intakes with reconditioned units from Germany. Two days later warning light back on again.

Question is has anyone else experienced this or had cause to find an incidental fault such as a sensor impacting fault? DrG have you perhaps come across this? Very frustrating and expensive so far.

[fatboy b]

How old is the car?

Less than 6 years, then surely covered under consumer protection.

[Andy JB]

Car is 2009 - new fault code again as before 4120 Intake Manifold Runner same as last time except its been replaced since - so could anything else be causing this as a knock on effect?

Dr G ?