My friend and I are working on a 91 Olds Cutlass 3.3L He is having some hesitation at both low and higher speeds. Engine light comes on, usually after acceleration, and goes off sometimes. The computer was cleared before codes were read. We pulled codes 26, 27, 28, 29, 34. This is the breakdown We cleaned the MAF sensor, checked for vacuum leaks, and checked all connectors. Codes still present. Any ideas?