I just got DC headers and the Apexi N1 installed on my 98 lude. I kept the old cat with the same o2 sensors. When I was installing the stock cat I noticed both o2 sensors were very dirty. Could this be the problem for the jerk at acceleration and higher speeds? I replaced my entire ignition (plugs, wires, cap and rotor) a month ago.

 

Was it jerking while accelerating before the exhaust work?

If so, it may be the mysterious Prelude Hesitation. IMO, it is usually caused by a faulty knock sensor pulling timing sporadically, causing jumps in power. Hence, the hesitation.