EXHIBIT 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement (Form S-8 No. 333-                    ) pertaining to the IMPCO Technologies, Inc. 2004 Stock Incentive Plan and IMPCO Technologies, Inc. 2003 Stock Incentive Plan of our report dated March 10, 2004, except for the 6^th paragraph of Note 1 and the 3^rd and 5^th paragraphs of Note 3, as to which the date is March 12, 2004, with respect to the consolidated financial statements and related financial statement schedule of IMPCO Technologies, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2003, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

Los Angeles, California

August 30, 2004