[onewhippedpuppy]

Is that Slate Gray? It looks very similar to my last 951, great color.

Adding to the theme of Bob's post, go through and replace every vacuum line and tee first and foremost. Vacuum leaks are the reason for a multitude of weird and frustrating 951 problems. Other stuff that is easy to miss would be having the injectors cleaned and balanced, replacing the engine coolant temp sensor (temp compensation for the ECU), and shifter bushings. If you don't have a record for the timing belt just do it, you really cannot determine age from a visual inspection and it's simply too expensive to risk. MAP sensor is a really nice upgrade over the AFM, you'll get better power and MPG. Add a boost gauge as boost spikes can easily toast your head gasket, I used a 968 pocket under the radio and installed the boost gauge in place of the clock. Assuming the exhaust is factory, adding a downpipe will give you quicker spool and more power, but if you keep the factory rear section the sound won't be obnoxious.