OldArmy

Guys I had the same problem with my 2001 Silverado 5.3. In California. What a pain... After spending days and north of $100 at the shop running monitor checks and idle tests (to no avail), here's how I fixed it myself: 1. Disconnect the battery. 2. Change the plugs, wires, clean the Mass Air Flow Sensor, and clean or replace the air filter (everything in front of the injectors). 3. Add a bottle of Lucas Injector Cleaner to the tank. 4. Reconnect the battery. 5. Run the silly drive cycle a couple times with the tank about 1/2 full. 6. Then drive another 50-80 miles for good measure. 7. Say three Hail Mary's. 8. Check the scanner for a reading like "Test Complete" I don't know which of these steps did the trick, but one of them worked! ps - if your plugs are frozen stuck, use a product called Aero-Kroil. NAPA sells it behind the counter in Cali. It's like Liquid Wrench on crack.