If one code doesn't work, try the other code.

PEKNAYLE / PAXNAYLE Play with 9 lives
GXSZZVVK / GZNXGVVK Infinite lives
GEKYSZZA / GAXYSZZA Qualify every race!
PEUYXZLA / PAOYXZLA Ruff Trux after every race
PASYNALA / PEUYYYLA Kid out of game after every race
GEKNIYAA / GAXNIYAA Start on race 5
PEKNIYAE / PAXNIYAE Start on race 10
TEKNIYAE / TAXNIYAE Start on race 15
LOKNIYAA / LPXNIYAA Start on race 20
AOKNIYAE / APXNIYAE Start on race 25 (Final Race!)
GESYOZPA / GAUYOZPA Win Championship race!
AAOEIAIA Faster Boat acceleration
AAOEGAIA Faster Sports Car acceleration
AAOETAIA Faster Formula 1 acceleration
AAOEYAIA Faster Turbo Wheels(tm) acceleration
AAXAAAIA Faster 4x4 acceleration
AAXAZAZA Faster Tank acceleration
AAXALAIA Faster Chopper acceleration
AAXATEPA Quicker Boat deceleration
AAXAIEPA Quicker Sports Car deceleration
AAXAYEPA Quicker Formula 1 deceleration
AAXEAEPA Quicker Turbo Wheels deceleration
AAXEPEPA Quicker 4x4 deceleration
AAXELAZA Quicker Tank deceleration
AAXEGEYA Quicker Chopper deceleration
YAEAZAPA Higher bounce for Boats
IAEAPAPA Higher bounce for Sports cars
YAEALAPA Higher bounce for Formula 1's
YAEAGAPA Higher bounce for Turbo Wheels
YAEAIAPA Higher bounce for 4x4's
YAEAYAPA Higher bounce for Tanks