inge

Hi,I live in Norway andown a 1998 venture and I changed the head gaskets earlier this summer.After the repair of the gaskets the cardeveloped a new problem that wasn`t there before.
When i drive at 1500 rpm the car doesn`t run smooth but bucks?(dont know if it`s the right word,exuse my poorenglish),and it will often stop idling when the car stops for ared light etc. When i push the accelator-pedal fast,the engine hesitates before reving up.I read the code on my diagnostic tool, and it says p0134 all the time.Can drive for two minutes and the code come .I have changed the upstream oxygen sensor with a new one and measured the voltage on theharness to be 12 volt on the heating but i only got 0,20 volt into the oxygen sensor from the pcm.Haynesmanual says that the correct voltage should be 0,40-0,45 volts.Can this cause this problem and does anyone have an idea on how to fix it?Is it possible that some other sensors can cause this code,or maybe an vacum-leak?Iam really desperat now because my wife drives this car and she is giving me a hard time to get it fixed! greatful for any suggestions,Thanks