The codes that are showing up on obd2 are P0134, P0154, P0306, P1351. Its almost like its not shifting on time, sometimes it will only go 20 - 25 mph going uphill. I've replaced the distributor cap along with the rotor wheel, new ICM, both upstream 02 sensors, New TPS, New MAS, all the spark plugs were recently changed so they should be good. I don't really know what else to look for so I figured I would try my luck on here before I get a professional involved. And by the way this is a 98 gmc jimmy 4.3 4 wheel drive, with 230,000 miles on the whole thing.