I have a 1995 toyota pickup with a rebuild motor in it. To my knowledge the exhaust has never been changed except for the manifold. The motor hesitates every so often what could possible be wrong? O2 sensors , cat converter

 

When was the fuel filter last changed ?. If the 02 sensor has over 50.000 miles on it, then it needs to be replaced. Make sure to use a Denso 02 sensor, its an oem replacement. Don`t use a Bosch 02 sensor, they don`t work well in toyotas.

 

I changed the fuel filter, the spark plugs, wires, and rotor cap at the same time not that long ago.

 

could be an o2 sensor, my BMW has a similar issue in which my next fix to try is an 02 sensor. At least the front one that controls fuel trim. O2 sensors don't have to throw a code to be bad.

 

So I'm probably going to replace the entire exhaust. what are some people thoughts header exhaust size etc. It is a daily driver and hunting rig i what something to get me a little more power thats not super loud