A cytochrome P450 monooxygenase that selectively catalyzes the epoxidation of 14,15 double bond of (5Z,8Z,11Z,14Z)-eicosatetraenoic acid (arachidonate) forming 14,15-epoxyeicosatrienoic acid (14,15-EET) regioisomer. Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (CPR; NADPH--hemoprotein reductase). an organic molecule + O2 + reduced [NADPH--hemoprotein reductase] = an alcohol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = 14,15-epoxy-(5Z,8Z,11Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] Lipid metabolism; arachidonate metabolism. Expressed in liver as well as in extrahepatic tissues including brain, kidney, lung, heart, and intestine. Belongs to the cytochrome P450 family.