And the fuel filter was changed when/ever?

Take it out and give it a good thrashing!

It could be that it is a 90 BHP model, which are a bit lethargic. MAF is a good call - just becuase a replacement was fitted doesn't mean it's any good - there are lots of cheap copies around that are useless. Otherwise it could just need the throttle cable adjusting. If it doesn't smoke or rattle, then it's unlikely to be anything serious, so probably worth a punt.

And a faulty MAF on the 90bhp models doesn't bring on an engine management light.

A decent diagnostic check with LEXIA will soon show where the problem is.

So I bought the car! Drove it to my mechanic, and it sat on the motorway no problem at 65-70, but definitely lack of power,as going up hill meant dropping a gear. No noise or smoke and very smooth. The car was cheap enough to take a punt,and if theres anything needed,then hopefully I can take bits off my old C5. I will let you know how I get on guys. Thanks for the advice

I thought I would update this thread. I took the car to 2 different garages who both put their diagnosis machines on,and nothing showed up. One suggested the turbo might have went,so I bought one off ebay. This was wrong one!Then took old one out to get reconditioned. There was nothing wrong with it(stop laughing!). Garage is guessing there is some blockage that is preventing the turbo coming on. Took it to main Citroen garage to see if their diagnosis would show up. They advised that they would need 3 hours to solve the problem. They quoted £360! I quickly (ok,slowly) drove out their garage. So I'm still driving the car and hoping engine managment light comes on at some point,so I can find out the problem.

I know there is a lesson to be learned here. Something about taking a chance on a car that isnt running right! On the plus side, it has 4 electric windows, 2 more than my old C5.

I never mentioned earlier,but its the 8v 2hdi 110bhp. If that makes any difference

Thanks again for your suggestions guys

MAF sensor or EGR valve are likely culprits. Find a local garage which is popular within the taxi trade. The Peugeot E7 hackney shares the same engine and any mechanic used to maintaining taxis will be well versed on their common faults. If you were near me I'd direct you to the workshop I use for my trade motors, they've always a workshop full of E7's in various states of disrepair. This engine is fit for 500k if maintained by someone who knows what they're doing, in fact I know of one E7 owner with in excess of 800k on his without any major work before it had to be taken off the road because of its age.

Hi. The previous owner tried changing the MAF sensor with no change. One of the garages I took it works with hackneys! Would EGR not show up on diagnostic machine? My other C5 has done 195k miles ,and thats why I took a chance on this one. I'll get someone to check these. Cheers

A faulty MAF will only normally affect the power at around 2000 rpm and below. Mine had several faults including difficult starting when hot, running on, and lack of power, it turned out to be the pressure regulator on the back of the HP pump, it contains a very fine mesh stainless steel filter and this can get clogged.

www.ebay.co.uk/sch/i.html?_odkw=peugeot+406+hdi+es...0

Edited by Peter.N. on 06/04/2017 at 00:24

Would've expected a gummed up EGR to flag up with a glowing management light but it doesn't always plus I believe it's possible to remove the bulb on these if I remember right. Not something I've done by the way.. Does the engine management lamp come on with the ignition? I'd try another garage if they've not been very proactive about solving this. Depending on where you are there's probably a few workshops favoured by the taxi trade. I'd get them to check the MAF sensor again, could be the last owner was wrong or lied to by another garage. Often the connectors can corrode so it might be this. I'm assuming you've done the basics such as taking a look at the air filter to see that it's not clogged or soaking and there's no leaks in the pipe work for the turbo? A good auto electrician may be worth seeking out but corroding electrical terminals are common on older French metal and can cause all sorts of strange symptoms.