Surging at cruise speed and p1131 code

[Kimppu]

My '96 4.0 OHV surging and bucking when I'm driving cruise speed between 1500-2100 RMP. It have done that about two moths now and only when the engine is totally warmed up to normal operating temperature. Yesterday I've got MIL on and I pulled out the codes and there was P1131 Lack of HO2S switch - sensor indicates lean. Here is list below what I have fixed without success:

- I have cleaned MAF with alcohol
- I have changed TPS sensor

What next?

 

[brucefrombruce]

I have been having this same problem with my 96 OHV, but the only recurring code I have had is 1152 - Lack of Upstream Heated O2 Sensor (HO2S21) Sensor Indicates Rich Bank # 2.

I also had a code 0300 - Random/Multiple Cylinder Misfire Detected, but this code has not come back in about a month.

I have cleaned that MAF, replaced the plugs and wires but I still get 1152 and the surging/bucking still exists.

I am wondering about replacing the coil pack as a next step. Any way to test the coil packs function?