The court shall not issue a declaratory judgment or decree under this section in any proceeding unless it determines that the petitioner has exhausted all available administrative remedies within the Internal Revenue Service. A petitioner shall be deemed to have exhausted its administrative remedies with respect to a failure of the Secretary to make a determination at the expiration of 180 days after the date on which the request for such determination was made if the petitioner has taken, in a timely manner, all reasonable steps to secure such determination.
The 2-year period in section 6532(a)(1) for filing suit for refund after disallowance of a claim shall be suspended during the 90-day period after the mailing of the notice referred to in subsection (b)(3) and, if a pleading has been filed with the Tax Court under this section, until the decision of the Tax Court has become final.