If you have never changed an air filter on a Citroen Xsara Picasso 1.6 hdi, you have never lived.... The filter is behind the engine...:doh:doh
Engine top cover off.
Disconnect air pipe to filter.
Disconnect engine breather to top of rocker box
Disconnect pipe from filter to tubo after unplugging the MAF
Remove MAF and associated pipe work.
Using an Allen key, attempt to undo three screws that hold the housing together.
Get another allen key of the same size as you have dropped the other one behind the engine, as you have scrapped your knuckles on the sharp edges to the body work.
Get a plaster, and clean up your knuckles as blood is dripping everywhere.
Now, wiggle the top over off the air filter, and attempt to remove the cover from the rear of the engine via the near side.
Hey presto.... there is the fiter, try to remove it, and get any leaves and dead rats out of the lower box. Fit new filter, and spend a few minutes trying to align the plastic clips before you try to refit the allen key screws, have a spare allen key handy, as there isn't any room to turn it to tighten it, when assembled, try to align the filter onto the two studs that supposed to hold the filter in place, then re- attach the pipework etc etc...
Now compare it to my 2.7td Mav...
unclip 3 clips on filter housing, lift filter lid off.
unscrew wing nutted bolt, swap filter, refit bolt, refit filter in box, clamp up....
Job done.
2 minutes max and that includes opening and closing the bonnet.:thumb2