M5 Guru (>2000 posts)
Join Date: Nov 2010
Location: Sanborn, NY
Thanked 252 Times in 214 Posts
Back story: Last week I replaced the passenger side CPS and passenger side VANOS solenoid orings. (I didnt have time to do the orings on the other side) Reason for replacing was more for PM than any previous codes or SES. (Actually the SES has never been on until this weekend)
Last Thursday I drove to work fine, started the car for trip home and it stalled once when I was backing out. A minute or so later the SES came on. Pulled codes that night with my MAC scanner (OBDII) P1350, P1354, P0316, P0171, P0174. I cleared them thinking they were triggered when I stalled it, and shame on me for not letting it warm up for another minute before I started to drive. The car exhibited no driveability symptoms.
I started my journey to TimmayFest and was cruising at 75 mph (about 150 miles into the trip)when the SES came on again. Still no symptoms, gas mileage stayed the same (25mpg). Stopped for lunch 100 miles later. Went to start car and it stumbled and misfired badly, barely running. In fact it stalled once. I tried feathering the throttle to see if it would "clear out" to no avail. On the third or so attempt to start, it started and idled normally, like nothing happened. Engine would then rev out in neutral and under load. Car ran fine the rest of the day. Next started cold ok, a tad rough for a few seconds. Later in the day after shutting it down hot and restarting hot the same thing happened. Today cold start it idled rough and stalled once, but it didn't act the same as before... not total misfiring, I was able to rev it.
Got home today and borrowed a Peake tool. Here are the codes: AE AF CD CE D1 D2 D3 D5
They seem to be similar codes between the OBDII and Peake. I'm sure some will suggest I check for vacuum leaks, but I doubt it is a vacuum leak because it does not occur all the time. Another reason I doubt it is a leak is after 3 or so attempts to run the engine it starts and idles fine. No vacuum leak will fix itself that suddenly...
That being said I am open to all suggestions on where to start looking.
UUC dssr and shifter
Supersprint headers with Tubi catback
JED lightened flywheel
258,000 miles and counting...