406 HDI 110 Intermittent Power loss

[Midgetmax]

Hi, I recently bought a 406 HDI 110 T reg (99?) Estate c. 130k miles as a load lugger/tow barge etc.

Intermittent fault getting more common - with no warning at all car goes into limp mode (I think). Huge power loss and won't rev past 2.5ish-k, engine management light comes on. It will drive for ages like this, still enough power to drag the trailer along but it does get a bit sluggish on hills! If I stop and switch off the power's immediately restored to the rudest of rude health when I restart. The EML light stays on for a couple of days then goes out all on its own.

It's happened about 4 times over the last month but the frequency is increasing. I ran it for a month before it happened first time with no problems.

I don't know the service history of this bargain basement purchase!

Any ideas? No-one round here (Devizes, Wiltshire) has a code reader without going to the local Pug garage and my mortgage is already max-ed without doing that! I've searched the archives and can't find a similar fault that gets better then re-occurs.