bucking and hesitation 95 pick-up

[pethia]

95 2wd pick up w/ 4 cyl.eng.I get bucking mostly when eng. is cold and when I am in a higher gear. It is far less prevelant after engine has fully warmed up.I done done following in past year.-new rotor, cap and wires-new air and fuel filter-new oxy. sensor-new plugs.any thoughts?thanks

[Rev_D21]

Did you replace the o2 sensor with an OEM one or did you splice in a Bosch universal?

[pethia]

I think it was a universal....what do you think?

[Rev_D21]

Well an o2 sensor only runs on .5 volts roughly and by cutting ans splicing in a universal you add resistance to the circuit which could be throwing the ecm a curve ball.