Ive changed fuel line filterf and plugs. New wires repaced at 77k. The battery may have a dead cell. It has been a while since I changed gas cap. What do I need to check or do next?
Thanks, Allan

Perform tests in Sections A and B below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563.html#post219438

Begin by:

. Testing all under-dash and under-hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post252145

. Perform K-Test on ECM.

What year Civic and what engine do you have? All attention needs to be focused on getting the CEL to go off after 2 seconds, when the ignition switch is turned to ON; otherwise, the engine won't start.

CELs staying on are caused by blown fuse (usually under-dash Fuse No. 24 or 12), failed ECM, bad main relay, or bad ignition switch.