ok guys, here it is. the cat. i have the same thing going on with my 97 and ive been discussing this with some guys. let me guess, when its cold and running high to warm up at a grand it doesnt do it, but after it warms up and goes into open loop it starts to "chug" but more like bogs right, but it doesnt do it all the time. its the cat, its backing up exhaust into the engine and cant reburn burnt fuel so it "chugs" or "bogs" down. believe me, it aint your injectors specially being newer cars. granted it wouldnt hurt to check your plugs and other routine maintenance. im getting ready to install headers and delete my cat.
