S10 Rodeo

I have an 89 S10 with a 2.5 and 255,000 miles. It has started bucking and jumping like a rodeo bull lately. I checked the engine code and got a 15, 32, 35 ,44. I put a new egr vavle, coolant temp sensor and O2 sensor on it. It runs worse than before. I have not put an IAC valve on it yet. Could that cause all the stalling and jumping and missing? What else could it be? It runs good and dont smoke other than this. Its at its very worse cold and at low engine rpm. But it can do it any time.

I have an 89 S10 with a 2.5 and 255,000 miles. It has started bucking and jumping like a rodeo bull lately. I checked the engine code and got a 15, 32, 35 ,44. I put a new egr vavle, coolant temp sensor and O2 sensor on it. It runs worse than before. I have not put an IAC valve on it yet. Could that cause all the stalling and jumping and missing? What else could it be? It runs good and dont smoke other than this. Its at its very worse cold and at low engine rpm. But it can do it any time.

Good AC-delco plugs and good plug wire and coil and cap rotor and or/coils?
Check plugs and plug wires and ign coil for proper spark to all plugs.
Post back what you got and you find there.