I just bought a 1999 3/4 ton with the 6.0L, 198K miles but runs great. I drove it for a couple days and then got a check engine light, code is a 174, Lean Bank 2. I didn't notice any performance issues so I cleared the code and after one more day it hasn't come back on. Would you guys recommend checking some things out that might have caused the problem or wait and see if it comes back? The truck does have aftermarket dual exhaust behind the cat., can that mess with any of my O2 readings? What else can I look for that might cause this code?

Thanks for the help guys

I just bought a 1999 3/4 ton with the 6.0L, 198K miles but runs great. I drove it for a couple days and then got a check engine light, code is a 174, Lean Bank 2. I didn't notice any performance issues so I cleared the code and after one more day it hasn't come back on. Would you guys recommend checking some things out that might have caused the problem or wait and see if it comes back? The truck does have aftermarket dual exhaust behind the cat., can that mess with any of my O2 readings? What else can I look for that might cause this code?

Thanks for the help guys

if these O2 sensors look like they are original change them ...the upstream sensors are critical...these control emissions...

also any vacuum leaks,,,possible intake manifold leak...also the exhaust manifold bolts can break off causing this..

make sure the O2 wires are not damaged melted,connectors good ..