Several strange issues.. + One especially concerning one!

[ySo]

Anyone have any ideas on why the following keeps happening on my 2000 x5 4.4i auto:

> The car randomly won't lock/unlock using the fob, 1 minute it works the next I have to open manually. Can go days either way too.

> Passanger door randomly won't open from the outside or inside handles **To temp "fix" this I have to repeatedly lock and unlock the car with the fob or the button on the centre console.

> Right front indicator bulb wasn't working for a while and when I indicated right the green flashing arrow blinked/ticked really fast **this one randomly fixed itself a while back, didn't change the bulb or anything it just started working again - just another example of strange goings on

> Check rear brake lights warning text on cluster every start yet the brake lights work fine *previous owner changed them to LED's.

> Drivers door can only be opened from the inside *I changed the carrier after it froze/broke last winter - assume it's gone again, haven't checked yet.

> The boot sometimes pops open after starting the car / possibly when I shift to drive.

> If I open the boot myself and close it the fob won't lock/unlock the car. *To get it working again without fail everytime I have to open/close the boot again.. Next time I open the fob won't work again etc etc - repeat.

THE BIG ONE:

If I put the foot down (not necessarily boy racer style but enough to have power to overtake) the car loses power... I can't overtake if I need to put the foot down. It's as if it's chocked somewhere. Whether air/fuel restriction I don't know. When I first got the car a year ago if I put the foot down it flew (4.4i v8!) and was a smooth, sharp increase. Now it's puttering along. **After a certain speed it seems to pick back up. I think it's the 40-60 range it struggles with.. Initially the car goes to a high rev and sticks there but speed only creeps/jump up randomly.

I know this is a lot but appreciate any help that can be given.

Should mention car had a full service about 2k miles ago, air/fuel/oil filters, spark plugs etc

[Horizon]

THE BIG ONE
when I had my 840 Ci I had a similar problem it was fine until I booted it in Kickdown, then after a matter of. Seconds it went into limp mode. Had the codes checked and it came up with misfire cylinders 1-4
The garage said maybe plugs, coil packs etc. I doubted this, then one old timer at the garage said did I hear any rattles on start up. Yes I did, the exhaust used to rattle when cold.
Get under the car bang on the Cat, it had broken up inside and was restricting the exhaust gasses from getting out, backing up on the engine, causing the misfire on that bank.
Enquires about a new cat at BMW £750 + VAT  :-[ :-[
Euro car parts £250
Had it fitted job sorted, turns out the other side had been changed before as I found the paperwork amongst the service history.
Someone else on here had the same problem with an X5 too

[Steamyrotter]

+1 on the battery..
Can affect an awful lot of things..

Have you tried the japanese reset??

Disconnect battery for 10 ish mins then re-apply power.
May clear some of those niggles...

May not but a cheap thing to try either way...

[ySo]

Thanks guys, will look into the battery. Never had an issue with it, but not sure how old it is either.

Regarding the power loss that's my biggest concern, might have to take it to an indy to get checked out as I doubt I'll be able to get to the bottom of it.

[X5Sport]

Amazon quite often have deals on CTEK so may be worth a look.