Have been lurking and reading posts for awhile, for the first time I'm experiencing a problem that doesn't seem to be already answered.
05 Deville, 77K miles, typical usage is work commute in fairly heavy Houston traffic.
I experienced the P0171 and 0174 lean bank codes. Looked around and found a vacuum leak, the 90 degree PCV boot that goes into the intake plenum. Since the car was
running fine, I was lazy about repairing it and let it go for a few weeks.
I started experiencing some very hard shifting, after the car had been running for awhile and was fully warm. I mean, BANGING the 1-2 and 2-3 shifts. I would anticipate it and throttle back to lessen the severity of the hard shifts.
So finally I got off my butt and replaced the 90 degree boot, which was more of a PITA than it should have been, not a lot of room to move and the only boots you can find are the universal Dorman type.
I've also had a pretty good PS pressure side hose leak which I'm going to fix in the AM, the engine isn't soaked but its used about 2 quarts over the last month.
About 3 days ago I noticed that RPM's were very high going down the freeway. I popped into an auto parts store and they pulled a P1811 code (maximum adapt and long shift), and an intermittent knock sensor code (sorry I forget the code, possibly P0342?).
After fixing the vacuum leak a brief road indicates that the car still isnt' shifting into 4th/od (not sure which is correct, its a 4th gear or true OD).
Any ideas? I've disconnected the battery this evening and will let it sit overnite to see if that clears anything out, thanks in advance for your help.