Catalyzes the hydrolysis of acyl-CoAs into free fatty acids and coenzyme A (CoASH), regulating their respective intracellular levels (PubMed:11171266, PubMed:14660652). Active with both medium chain and long chain acyl-CoAs (e.g. 12:0-CoA, 14:0-CoA, 16:0-CoA, 18:0-CoA, 16:1-CoA, 18:1-CoA, 18:2-CoA and 20:4-CoA) as substrates, palmitoleoyl-CoA (16:1-CoA) being the favorite substrate (PubMed:11171266, PubMed:14660652). a fatty acyl-CoA + H2O = a fatty acid + CoA + H(+) dodecanoyl-CoA + H2O = CoA + dodecanoate + H(+) H2O + tetradecanoyl-CoA = CoA + H(+) + tetradecanoate H2O + octadecanoyl-CoA = CoA + H(+) + octadecanoate (9Z)-hexadecenoyl-CoA + H2O = (9Z)-hexadecenoate + CoA + H(+) (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + H2O = (5Z,8Z,11Z,14Z)-eicosatetraenoate + CoA + H(+) H2O + hexadecanoyl-CoA = CoA + H(+) + hexadecanoate (9Z)-octadecenoyl-CoA + H2O = (9Z)-octadecenoate + CoA + H(+) (9Z,12Z)-octadecadienoyl-CoA + H2O = (9Z,12Z)-octadecadienoate + CoA + H(+) Insensitive to feedback inhibition by free coenzyme A (CoASH). Optimum pH is 8.5-9.0. Lipid metabolism; fatty acid metabolism. Homotetramer. Predominantly localized in the peroxisome but a localization to the cytosol cannot be excluded. Mostly expressed in leaves and flowers, and, to a lower extent, in seedlings and siliques. Belongs to the C/M/P thioester hydrolase family.