My silverado with 5.3 liter has a changing code.It usually says random misfire, found it was #2 and #6 cyliders, sometimes it’s only number 2. The misfire goes away at anything above idle, garage noticed this. Put in new plugs, coils,2 injectors, crank sensor and plug wires. Idle seems to drop lower once in a while but not often. What should I look for next?
A worn/stretched timing chain.