Stainless Steel Headers For Chevy Cobalt/HHR (2005-2010) with 2.2/2.4 EngineWake up your Ecotec and get the throttle response the GM Delta platform was missing from the factory with this high flow stainless steel header upgrade. Performance Stainless Steel Header for Chevrolet Cobalt & HHR (2. 2L 2. 4L Ecotec) If you drive a Chevrolet Cobalt or HHR equipped with the naturally aspirated 2. 2L or 2. 4L Ecotec, you know these engines are reliable, but they feel choked at higher RPMs. The factory exhaust manifold is a cast "log"