I have had 2 previous surgeries. Now have either scar tissue or overgrowth at L5 from ltcage. Will a epidural steroid shot help?

Hard to know. without more info about you specifically. Sometimes epidural injections help a lot. When they don't help you may need to consider other options like radiofrequency ablation or even spinal cord stimulation. Newer treatments like stem cell terrapins are also available but are investigational at this time and insurance does not cover them.
Not valuable. Epidural steroid injection works best when a nerve root is compressed and inflamed, if the injection is give at the correct level and side. But you describe post-operative scarring and arachnoiditis, and this is indeed not a situation where the esi will benefit your problem. Get a consultation from a pain specialist, and decide your next steps.