I have a stripped spark plug thread on my 1998 BMW

The spark plug should not come out if it is the proper application spark plug with the correct torque. Sounds as if the plug hole may have damaged/stripped threads which can lead to a costly repair. There is an alternative repair for this without removing the cylinder head. A Heli-coil can be installed into the damaged plug hole. If installed correctly, this repair can last the life of the vehicle at a fraction of the cost

Here's a link that will help you.
http://www.youtube.com/watch?v=JLDo7Jk78ac&feature=youtube_gdata_player

There are kits for stripped out spark plug
threads in the cylinder heads

Google the issue, lots to read

You can find the procedure here
https://resetoillight.com/bmw/oil-change-light-reset-bmw-528i-1998-1999-2000/

might be a relay, here is a thread that will assist you, Tim:

http://www.bimmerfest.com/forums/showthread.php?t=263500

The fact that you have a backfire noise that you can trace to just one cylinder makes it sound like a spark plug could be loose or broken. Pull out your spark plugs and examine them. On a '98, that eill mean pulling off the plastic cover, then removing the coils (need a 10mm socket, be careful with the ground wires) and then reach down in with a small spark plug socket on a long extension.
Also, look for a massive air leak on the intake. Take apart the air tubes from the air filter up to the throttle body looking for air leaks. You could also have a leak at the intake manifold gasket but you may need help to check for that.

The issue seems to be related to the spark plug threads. The spark plug is either not tightened down or the threads are stripped, and during the compression stroke when pressure is applied inside the combustion chamber, the pressure leaks thru the spark plug threads and blows off the spark plug boot. If the spark plug is not tightened and the threads are ok, then tightening the plug will resolve this issue. If the spark plug threads are damaged, then the threads will need to be repaired, and will require the cylinder head to be removed to repair the stripped threads. Taking the cylinder head off requires the engine's top end to be ripped apart and re-assembled....big job.

Not exactly sure what you need?
Standard Rules:
Use a Spark Plug Socket to remove and install Spark Plugs.
Replace (remove) one Wire at a time from one Spark Plug.
Replace One Spark Plug at a time. Use Anti-Seize Grease applied moderately to the threads on the new Spark Plug.
Using a Socket (with a extension) START all installations using your hands. This prevents cross-threading and stripping of the threads inside the Heads.
Standard Torque 15-20 ft-lbs.
Replace the One Wire connection to that One Spark Plug.
Replace that One Wire connection to the Ignition Coil.
Go onto the next Spark Plug using the above Rules.
Repeat.

For the 3.4L V6:
Firing Order:
1-2-3-4-5-6
Cylinders:
......(back)
1.......3.......5
2.......4.......6
......(front)
Ignition Coil Connections:
............(back)
.|.5..2.|..|.3..6.|..|.4..1.|
............(front)

replace relays and fuses for the power seat and windows.change dash light bulbs.if bulbs are good you got wiring problem check ground wires.