Engine light comes on from my knock sensors

This is a tech bulliten on your code:
AUDIBLE SPARK KNOCK (DETONATION), MIL ILLUMINATED, DTC P0332 SET (REPLACE REAR BANK KNOCK SENSOR & RTV AREA AROUND SENSOR) TECHNICAL SERVICE BULLETIN Reference Number(s): 02-06-04-023A, Â Date of Issue: Â June, 2002 Superceded Bulletin(s): 02-06-04-023 Related Ref Number(s): 02-06-04-023, 02-06-04-023A ARTICLE BEGINNING DESCRIPTION Audible Spark Knock (Detonation), MIL Illuminated, DTC P0332 Set (Replace Rear Bank Knock Sensor and RTV Area Around Sensor) Some customers may comment on a mild to severe engine ping (commonly referred to as spark knock), usually worse during acceleration and/or an illuminated MIL. Upon investigation, the technician may find DTC P0332 set. CADILLAC: 2002 Escalade, Escalade EXT with 6.0L Engine CHEVROLET: 1998-2002 Camaro, Corvette with 5.7L Engine; 1999-2002 Silverado, Suburban, Tahoe; 2002 Chevrolet Avalanche with 4.8L, 5.3L or 6.0L Engine GMC: 1999-2002 Sierra, Yukon, Yukon XL with 4.8L, 5.3L or 6.0L Engine PONTIAC: 1998-2002 Firebird with 5.7L Engine SECTION: 06 - Engine/Propulsion System NOTE: This bulletin is being revised to add Cadillac Escalade and Cadillac Escalade EXT to the Models. Please discard Corporate Bulletin Number 02-06-04-023 (Section 6 - Engine/Propulsion System). Here's what's involved, and yes frequent washin does make it worse!:

Shop around you might get it for less at a local shop if there is a good one in your area.