I found one vacuum leak in the hose that goes to the brake booster. I removed the OEM clamp and put a new on on. It still misses so I’ll check it again, for leaks, tomorrow morning. I put some cardboard under the car. It appears the slave cylinder is shot. The brake fluid is dripping off of the bottom of the transmission. Should the brake pressure be enough to pop the seal on it?
You said that there was some cobbed up wirring on the 02s. Out of curiousity have you checked the wiring for the MAF sensor? A damaged wires causing a partial short would throw a MAF code also.
If you want to get anywhere, you need to find out the BMW code numbers. None of the internet BMW resources available to you speak Advance Auto Parts.
http://www.pelicanparts.com/bmw/techarticles/Mult-Code_Reading/Mult-Code_Reading.htm
The 02’s were cut and spliced. I replaced them with new ones. The MAF harness is still intact with the factory wire cover, so that should be ok.
Thanks for the link! I think I know what the issue may be. This part:
One of the clips that holds it onto the manifold is broken. There’s a lot of extra stress on it with the added hoses to make it OBD2 compliant. It’s a $5 part, so I’m going to order that and a new slave cylinder tomorrow and hopefully this solves my problems.
That would just be a vac leak, is that all you have? Run the car and spray brake cleaner around it, if nothing changes, then its sealed up.
I’ve tried that and I couldn’t notice any changes. I then switched to soapy water and was able to find one leak in the hose from the valve cover to the brake booster. It won’t hurt to try again before I tear it apart for a 15th time 
It’s not just a simple vac leak, you wouldn’t get jumpy misfire codes. The BMW fault codes dont have just “misfire cyl 4” like P0304, they have “ignition coil 4” or “fuel injector 4.” Even if those things aren’t the problem, it tells you where to start your research. Luckily, it’s one of the most heavily documented DIY cars on the planet, so it wont be hard to figure out once you have the right information.
The Peake tool they use in the Pelican article is worth it if you plan to keep the car for awhile and, well because the car is haunted. Otherwise, slip a Keeler tech $20 for the codes and get his thoughts while you’re there.
Edit: While we’re on the subject of heavily documented DIY car, a happy Presidents Day gift for BMW owners: http://spaghetticoder.org/bmw/
Love civics. Grab a paper clip and you’re good to go. Lol. Goodlick rando. Atleast it’ll be worth it in the spring.
Thanks again for you advice and the link! I’ll take it to get the codes read with the proper tool so I have the right information!
Thanks. I’ll need it with all the gremlins in this car.
In for results, curious now.
Me too. Chris’s car is now the forum’s communal project. But we dont have to spend any money.
LOL…I’m goign to do what you guys said, get the codes properly read then diagnose the problem form there, before I waste more time and money tearing it apart again.
+rep thanks for the link!!!
Does anyone have a Peake code reader I can borrow for a day? At this point the car shakes horribly, due to misfires, and I can’t drive it more than a mile due to the slave cylinder, so driving it to Latham/Albany area is no longer an option for me. I had a local shop look it it. They tried to tell me it’s my coils, which I know work fine. They also used the same autozone scan tool that I use, just an upgraded model. I know they have a peake reader, but wouldn’t use it in front of me. I even offered them a few bucks too 
Could it be a cam or crank sensor?
Crank would cut spark and fuel.
Cam would let it run but like shit.
So would a major vac leak.
This happened right after the last head install right? Are you sure you plugged everything back together correctly? Wiring diagram to verify, see link I posted if needed.
Prob going to have to buy the Peake and sell it for 90% of what you paid in a few months when its running right. So close to being finished…
As far as I can tell everything is back together the way it was before. I even referenced pics I took before to make sure. I’ll probably end up buying the tool tomorrow. I’m going to put the S52 intake manifold back on it 1st. Then see how it runs. If it clears the misfires I’ll know it was with vacuum mess under the M50 intake.
Unless your M50 manifold has a crack in it somewhere, that wont change anything. If it’s not changing when you cover it in brake cleaner, it’s not a vac leak in those areas.