1997 BMW 740

Engine Performance problem
1997 BMW 740 V8 Two Wheel Drive Automatic 155792 miles

A failed smog check with the air injection result showing FAILED and faults codes showing MISFIRE DETECTED for CYLINDER#3, #6, #5, #2. How can this be repaired? Are these multiple problems?
August 23, 2010.

I believe there is more than one thing going on here. The air injection could be several things from a dead air pump to a broken vacuum hose to plugged passages inside the cylinder heads. The misfire faults could be due to intake manifold vacuum leaks or it could have just run out/low on fuel. Are you going to repair the car or have it done?

Dr. Hagerty
Aug 23, 2010.
I would like to do the work myself, although if having to open engine I will have to get a Pro. To do any major work. Does the air intake valve fail because of dirt build up? I will fill the fuel tank and new fuel filter, is the gas fuel fillter easy enough to access for changing out?
Thanks for your help.

Aug 23, 2010.