Repeated replacement of CKS on 2002 Pontiac Bonneville

P0336 CKS code with tach dropping to zero from 2000 then erratic. Code occasionally will clear then reoccur. Loss of power when climbing hill. Never stalls always starts. 160,000 miles. In park, MAF shows steady increase in lbm/min when increasing rpm

Asked by for the 2002 Pontiac Bonneville
As for the code ; Crank balancer tone ring in good shape with 'no' bent sections? I have seen these sensors installed without pulling the balancer, that is a mistake!! Not saying that is how this one was done,,, just saying.
Trying to fix the problem the garage replaced both the CKS and the CMS but the real problem was the ignition module. The old ignition module had just undergone 7 sequential tests and shown "good" but was defective nevertheless.... The car runs great thus far. The old module and CKS had been replaced in October 2012.