This study focuses on the Termomechanical Fatigue (TMF) analysis for an exhaust manifold. Bolt tension and temperature field has been applied in order to get variation on stresses, going from room load condition to a full load condition. The temperature field has been acquired from 1D simulation and adjusted to fit experimental values measured on the vehicle. Low cycle fatigue (LCF) has been considered to evaluate the exhaust manifold under the stress cycles produced by temperature fluctuation. Thermal and stress analysis have been performed by Abaqus package. An in-house code has been employed in the fatigue analysis. The bolt torque and the temperature field on the engine and exhaust manifold are the loads considered in the analysis.