Spluttering 04 Cayenne S on high revs

[mpronto]

My Cayenne has started spluttering after the revs of about 3800, from standstill I boot the throttle and all ok, when it reaches about 3k to 4k revs all the way to 6,900, she splutters, I have gotten the injectors cleaned out, as it feels as though it is starving of fuel intermittently, a couple of kilometers back I put in new coils and spark plugs, so I don't think this is an electrical issue, I'm thinking maybe fuel filter or pumps, the filter I can check, but how would I go about checking the pumps and where are they located, as I have heard that there are 2 of them!

[wvicary]

There are two fuel pumps but instead of just replacing parts why not take the time and check for fault codes and MAF sensor/boost data?

[mpronto]

There are no fault codes, so my reckoning is that it is dirty fuel lines or the pumps are dirty and when high pressure is required they cannot deliver.

How can I check for MAF sensor/boost?

Also, can I remove the pumps and dismantle them and check for debris?