It is probably spark knock from using a low octane gas. Try using a higher octane gas for awhile and see if it goes away. If it does then that is the problem. It will not hurt anything but it can be annoying. Lower octane gas burns faster and sometimes causes a pinging sound while accelerating. Some people say there valves are rattling but that is not the case.
Never, normally it will last the life of the engine.
It means that the computer has detected a fault in the emissions system. There is no usual cause. The ECU willl need to be scanned with an OBD2 scan tool.
That depends on the cause of the knock. Many people are incapable of discerning the difference between ignition pinging, a true "knock", and lifter noise. Lifter clatter can only be adjusted by a machine shop. If it's a ROD knock, that's only caused by too much clearance between the rod bearing and the crankshaft. In that case, the only option is to rebuild the engine. Same with main bearings, too much clearance between the main bearing and the crankshaft will cause a deeper knocking sound, but the cause, AND REPAIR, is much the same. However, it is possible to SOMETIMES use an oil with a higher viscosity to squeeze a few more miles out of an engine. That only works if the engine hasn't worn too badly. Another cause of engine "knocking" is when the spark fires too early. The "knock sensor" detects cylinder pinging and sends a signal to the computer, which then retards the spark making the pinging go away. The idea is that the computer keeps the spark timing as far advanced as is possible without introducing cylinder pinging. Doing that can significantly increase fuel economy. It's called a knock sensor, even though we typically call early ignition "pinging". The computer should be able to determine if the knock sensor has failed. A computer diagnostic code scan will give you a good idea if any of the electronic components have failed.
check the pcv valve
The Chevy Silverado provides a 4-speed automatic transmission. It has V6 cylinders. It has a gas type engine. It's fuel economy is 15/20 miles per gallon.
I have one with 289,000 miles with a gas engine and running like the day i bought it new
The engine oil should be changed every 3000-5000 miles
37000 original miles
Silverado 1500 gets 16/21
With a 5.7L engine, you can expect 11 mpg city, maybe 15 hwy. That is what mine gets.
33,000 miles!
I have had a 1996 Chevy Silverado for 5 yrs. 200k+ miles and I am getting about 13 miles per gallon.