My car has a big hesitation sometimes its gradual sometimes itslike you hit the rev limiter it does it between each gear only when the engine is pulling --goes away comes on strong shifts then does it all over again 2000 ta changed fuel fillter has 60* of fuel pressure at idle-- scan no codes but my 02s1 does not move up and down and holds around 800 o2s22 also holds around 800 the other sensor moves freely between lower no. and higher nos. could bad o2 sensors be causing this problem without throwing any codes. ive had this problem for about a year.. i dont think its a vacum leak