HELP close to setting this thing on fire.

[unknownE53]

so i have a 2004 bmw x5 3.0i and i keep having this problem with rough idle car sounds like a jet taking off when driving. I've scanned the car and came up with p1092 p0171 p0174 p0505, Misfire all cylinders (1-6) which seems to all be lean codes mostly on bank 2 , I've changed o2 sensors pre-cats I've tried swapping them the p1092 code does not move from bank 2 but I developed a lean code on bank 1 I've swapped multiple disas, idle control valve, maf . I changed the vacuum line on the intake boot going to the fuel pressure regulator which was cracked at the fpr still p1092 it all started with a p1093 which is rich that went away and p1092 developed couple miles after. the car drives ok alittle loud for a bmw id say, whenver the idle control code comes (p0505)even after swapping with a new one the car runs in limp mode high rpm while going 35mph and all fuel trims are at 0. car wont run normal until i reset the ecu.the p0171 p0174 always gets tripped pending on idle when the car warms up.any suggestions ? thank you in advance also this is my first post

[c-bass]

Welcome!

I was very VERY close to setting mine on fire recently because of a rough idle and misfires I was chasing for months.

First off...do NOT set the car on fire! The insurance company will not pay out. WALK AWAY!!

In my case I cleaned then changed my ICV, changed the spark plugs and coils, DISA, replaced the MAF etc, etc,. None of that made any difference.

Lean codes are a good indicator that there is a vacuum leak somewhere.
These engines are very prone to acting crazy when there are vacuum leaks and you can be throwing parts at it in circles.

If possible get your engine smoke tested. This will usually reveal where the issue is.

Have you checked your CCV? A clogged CCV can give you issues at idle and the mayo goop loves to build up in cold weather. Try and pull off your oil cap when the car is running. If it's difficult your CCV system might have problems.

Your valve cover gasket can contribute to issues if it hasn't been replaced recently as it gets hard over the years it doesn't seal as it should.

Other sources of vacuum leaks are:

The throttle body gasket

On the back right side of the intake manifold (if you're facing the engine) there are a couple of rubber caps covering unused vacuum ports. They get brittle, crack and can be a source of leaks.

The rubber around the DISA valve

Intake manifold gasket

Basically anything that is a gasket should be replaced at some point in these cars.

[RocketyMan]

+1 on the smoke machine mentioned above.

I recently picked up one and need to get baby-oil in order to fill the smoke machine. My plan is to take off the intake filter and just after the MAF put my tube of smoke in and determine where the leak is. To my understanding the throttle plate should still be open enough to allow the smoke to circulate the rest of the upper intake.

https://www.toolots.com/autool-sdt-202.html

This is what I ended up getting. I think I paid $169 for it on fleabay.

[upallnight]

What is the actual condition or health of the engine? What are the compression in each cylinder? Cylinders with low compression equate to low power output which the computer registers as a misfire.

Start with a compression test and go from there.