So I did some maintenance on my 04 mini cooper s which included: Supercharger oil change, water pump, water pump flange, crankshaft position sensor o ring, oil dipstick o ring. So after putting everything back together and starting it for the 1st time I get a code P1242: Secondary Upstream Manifold Air Pressure Sensor Signal Too High in Deceleration. And the idle is fluctuating between 1200-1600 rpm. I went looking around I know one of the things too look at is the bpv, which I did and once the engine was up to temp I could clearly see the lever moving back and forth. I also looked at the intercooler boots and they look fine. I also sprayed some of the vacuum hoses, to see if i could get a change in rpm and I didn't et any change. But to be fair the idle is fluctuating so much it's hard to tell. The other thing I did is I unplugged the front MAP sensor, the one by the intercooler, and the idle dropped back down to 900-1000 rpm. Not sure if that's normal or not. Any ideas?