1.4 100PS sudden power loss at high speed

[Defcon5]

A couple of times over the last few months, my 2000 Sport has totally lost all power on the motorway, its as if the throttle has suddenly stopped working - there is no response from the pedal at all.

It is rare, and the omly similarility is that it has done it when at a constant speed (60ish, light throttle). Never happened when accellerating.

Yesterday I noticed that when the fuel pump primed on 1st ignition, it was squealing.

Im going to guess that the fuel pump is cutting out occasionally at higher speeds and thats causing the loss of power. I have read the fault codes and got

17559/P1151/004433 - Long Term Fuel Trim Additive Air; Bank 1; Range 1: System too Lean

Which would also tie in with a faulty fuel pump I think?

Is there a single fuel pump? Can I change it myself?

Could anything else cause the cutting out?

[Silver!]

Had a similair issue with my MK3 POLO GT, but it done it at lower rev's too. Never showed any codes. Replaced lift pump, in-line pump and filter and some fuel pipes which were corroding.

[Defcon5]

Well I cleared the codes and have been using it constantly since. It has continued to do it several times since.

No codes are stored.

However, sometimes the idle is crap, with the odd misfire, a la failing coil pack.

Now could the coil pack be causing the cutting out? Im reluctant to start ripping out fuel pumps only to find its the coil pack! No misfires are recorded on VAGCOM, despite the fact I can feel and hear it misfiring it says no - just how bad does it have to be?

Also, whilst playing of VAGCOM the car is reading the intake air temp at 65 degrees? Is this likely to be correct? Thats a good 45 degrees above ambient, seemed a little high.

Edit - using the measuring blocks, and the misfire recognition one, occasionally it displays 1, then it goes back to 0.0. Is this due to some kind of refresh rate? And for some reason it turns off the misfire recognition once you go above about 1500rpm