General Motors Co. CEO Mary Barra will reappear before Congress on Wednesday amid expectations she will answer more questions about the widening ignition switch recall than she did last time.

During questioning from House and Senate panels in April, Barra deferred answers to many questions as she awaited the results of an internal investigation by Anton Valukas, a former federal prosecutor who conducted a critical investigation into GM’s mishandling of the ignition switch crisis. Barra has so far fired 15 employees. On Monday, GM more than doubled the number of vehicles on which it is replacing ignition switches or keys from 2.6 million to 6 million.

“When I was here 11 weeks ago, I told you how we intended to proceed with this matter,” Barra will say Wednesday in her prepared remarks before the House Subcommittee on Oversight and Investigations.

The subcommittee will also hear from Valukas, who will discuss his report and answer questions.

Energy and Commerce Committee Chairman Fred Upton, R-Mich., wants answers. The committee, which opened its investigation in March, wants to compare its findings with those of the Valukas report.

In his opening remarks, Valukas notes that GM engineers knew of a problem with the Chevrolet Cobalt from its development, received reports of accidents, but did not consider the problem a safety issue.