OK anybody whose had 227/228 codes (lambda control limit reached or P0171/174 codes engine running lean) more than likely its gonna be the lower intake throttle body rubber hose perished here's a how to how to change it..
T27 and a T30 torx bit
long nosed pliers
special jointed screwdriver tool with built in ratchet (handy but not essential)
time taken approx 45 minutes to an hour..
First we need to remove the pollen filter housing complete so we can remove the corner section on the passenger side wing area where the ECU box is to give us maximum room and make it easier to access the area were working
Release the 3 pollen filter cover clips and remove the cover and then remove the pollen filter
one of 3 quick release fasteners
Next unclip the 4 plastic fasteners above the engine which are holding the battery positive cable and the ECU conduit going over the engine and pull them out of the plastic trunking ready to remove the main housing
Plastic trunking clips
Now we have access to the 4 T30 torx bolts securing the pollen filter housing to the bulkhead undo these (they are captive bolts) and remove the housing by pulling it up and toward the front of the car..
1 of 4 torx bolts securing housing
What it looks like once out of the way
Next were going to remove the corner plastic section of the inner wing area this is only held on with 2 quick release fasteners (be careful these are not captive and will fall in the engine bay)
Slide the ECU conduit out of the plastic section and remove the section by pulling it out
Next remove the front air duct by releasing the 3 fasteners by pulling the centre rods out.
Unplug the MAF and loosen the jubilee clip securing the top hose to the MAF body.
Undo the 2 x10mm bolts securing the filter box to the inner wing and lift it up by tipping the rear end up and out .
Filter box removing
Next undo the jubilee clip on the top hose section at the plastic jointing piece attaching it to the lower section and pull it off..
jubilee clip at jointing piece.
The top hose is still attached by the 2 small hoses on the elbow, it needs to be pushed out of the way into the ECU box area, so there is more room to remove the lower section hose.
So the larger of the 2 small hoses pull it off its connection so we can push the upper hose out of the way and then we want to undo the T27 torx screw of the bracket securing the pipe assembly you have just pulled the hose off beforehand, so we can push that out of the way to give better access to the 2 jubilee clips we want to undo to remove the lower hose section.
Torx screw for bracket
Finally top hose pushed out of the way in the ECU box section. You could remove the top section hose altogether, but I chose not to as the plastic elbow piece on it with the 2 small hoses attached is fragile and has a nasty habit of breaking off.
Now we can access the main hose jubilee clip to the throttle body and the elbow hose jubilee clip to the ICV (I recommend a ¼ ratchet and a 6mm socket as space is still limited) undo these and pull the old lower intake hose off..
Jubilee clips location
Undo jubilee clips.
Now its off you need to swap the plastic jointing section that attaches the lower and upper hoses together over to your new lower hose section..
undo jubilee clip and remove plastic jointing section from old hose and fit to new lower hose..
Refit the lower hose section to the throttle body and ICV (there is a tab on the section which fits between 2 ridges on the throttle body so you correctly align it) and just refit everything else in reverse order.
New lower hose with jointing piece refitted to the engine
Old duff hose split at ICV elbow.