problems after adding aftermarket muffler

i added an aftermarket muffaur and since then at high rpm between 4 and 5000 the rmps will not do any thing and the car will kinda jump like i am taping on the gas does ne one know what could cause that email me and let me know

my neon did the same thing with a stock muffler and it was my cat maybe you need a high flow cat for the muffler or maybe you just need a new cat

lol a high flow car for a muffler? wtf lol

try resetting you computer, make sure all you plugs are ok. bsaic car care stuff 1st

why add a muffler...and i dont get why you are having this problem. maybe you added an aftermarket CAT BACK system...mufflers alone dont do anything and wont increase performance. and if your car is jumping, its probably not your exhaust system, its likley your ignition. try checking your plugs and batterys.

lol a high flow car for a muffler? wtf lol

try resetting you computer, make sure all you plugs are ok. bsaic car care stuff 1st

honestly can you even read ? it says cat as in catalytic converter