I disconnected the battery in my truck to clear the check engine light after replacing the evap leak detection pump now my truck is idling rough it never had a problem before my truck has 176000 miles but has been well maintained and never had real problems I fix the parts as soon as the check lights come on I tried to clear the codes with the battery but as soon as I turned it on it was idling rough but the codes are gone it’s pulling power and my lights are dimming back and fourth now please help

 

Sounds like you could have a connection problem. Check that the battery cables are clean, and have a snug connection to the battery.
Also check your grounds, make sure they are clean and tight at the engine and frame.
Hopefully cleaning up your connections will solve your problem. If not, you will need a multimeter/DVOM to go further.