What was found
ON DESCENT THROUGH 20,000 FT, THE IAS MIS-MATCH MESSAGE DISPLAYED ON BOTH PFD'S. CAPTAIN'S A/S INDICATED 221 KTS, FO'S INDICATED 206 KTS. AS DESCENT CONTINUED, THE FO'S A/S INDICATION CONTINUED TO DECREASE. ALSO, RECEIVED ELEVATOR FEEL, PITCH TRIM, SPLR OTBD AND RUD CONTROL CAUTION LIGHTS. C/W ABNORMAL CHECKLIST, SWITCHED TO ADC1. DIVERTED TO BOI AND ACCOMPLISHED A UNEVENTFUL LANDING. MAINTENANCE DRAINED NR 2 PITOT SYSTEM IAW AMM 34-11-06. C/W NR 2 PITOT SYSTEM LEAK IAW MTC 5341001, OPS CHECKS NORMAL. NO PARTS REPLACED.