They have been asked to put forth their stands on the charges by Saturday morning failing which the EC will take action without further referring the matter to them.
The show cause notices were issued following complaints and reports by poll authorities in Uttar Pradesh.
The Commission has already expressed "displeasure" at Verma's "biggest goon" remark against Modi.
Referring to Katiyar's speech made in Sant Kabir Nagar in UP on April 15, the EC notice quoted him as saying that the Muzaffarnagar riots were bigger than Gujarat riots.
He had reportedly said that "no attempt" was made by the UP government to check the riots and senior SP leader and UP minister Azam Khan was given a "free hand" to issue directions to administration officials.
Katiyar had said once Modi becomes the Prime Minister, riots will be probed and it will be "ensured" that Khan is sent to jail as he had "planned" the violence last year in west UP.
Addressing a public meeting in Kanpur on April 20, Verma had reportedly said that once Rahul Gandhi becomes the Prime Minister, Modi and his close aide Amit shah will be "jailed for life" for Godhra riots.
He had also reportedly said that as a 20-year-old, Modi had committed a "major crime" and had fled him home. He had said the BJP's PM nominee will never reach the PM's post and go to "graveyard".
The two have also been provided with copies of CDs carrying their remarks.