Last weekend I performed the spring cleaning procedure from gnttype.org, installed a big-mouth cold air intake, and a tps enhancer. The first time I hit wot my service engine soon light came on. I installed a scanmaster, which told me I had a malfunction code of 23, my MAT sensor. I picked up a new MAT sensor from the local auto parts store, which made my Service engine soon light go out, but I'm still getting a code 23, and now also codes 32 (EGR components) and 44 (O2 sensor). Should I replace my EGR valve and O2 sensor? And why am I still getting a code 23?