Hey...
Thought id share an opinion..
The mods you've done... 4-2-1, larger diameter exhaust pipes, removing cat con will ultimately result in better exhaust flow out from the engine.... ur powerband has probably moved up slightly higher in the RPM range..
If you want better low end torque, you're gonna need backpressure... but with ur current setup, backpressure has been significantly decreased....even with ur S Flow muffler..
Add that to the fact that your using an Auto Gearbox which is usually more sluggish than a manual during acceleration..
By the way, what is your exhaust routing like? Is it a straight setup? or is it following the original exhaust routing?
Straight pipe setups are no good when it comes to low end torque...
I suppose ur using a 1.6 right? Like shiroitenshi said, you cant expect low initial torque as with a 2.0 engine....There's no replacement for displacement...
Well hope that clarifies the possible factors to ur problem...
Solutions? Depends on what you want...
Not so simple to get good low torque whiles having good high rpm torque from a small displacement engine... Considering ur using an auto, i think smaller diameter exhaust setup with more backpressure is much better... coz then u'd save fuel, whiles having valuable low rpm torque.... Real ideal for city driving.... (im guessing city driving is more important considering ur choosing an Auto)
If you're looking to have more fun with ur car.... Meaning ur going to be driving more "enthusiastically" or go for track days, then definitely high revving is the way to go... especially from a high compression 1.6 engine... Which would then be much better mated to a manual gearbox...
So unless ur willing to spend a lot of money to squeeze more power from ur engine...
U gotta decide what kind of car you want out of ur Civic ..
hope this helps...