EX-23 4 p10k23.txt PIONEER EXH 23.1 TO 2001 10-K EXHIBIT 23.1 CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference in the Registration Statements (No. 333-35087, No. 333-35165, No. 333-39153, No. 333-39249, No. 33-44851, No. 333-35085 and No. 333-35175) on Form S-8 and (No. 333-42315, No. 333-44439 and No. 333-39381) on Form S-3 of Pioneer Natural Resources Company and the related Prospectuses of our report dated January 25, 2002, with respect to the consolidated financial statements of Pioneer Natural Resources Company included in this Annual Report on Form 10-K for the year ended December 31, 2001. Ernst & Young LLP Dallas, Texas March 6, 2002 100