problem after CAI

hi,

i own a honda fr-v 1.7.
the engine is similar to the previous
model of honda civic (vtec sohc engine).

i did a cold air intake mod and swapped to
iridium spark plugs. the few additional hp
gave quite a nice drive. but this mojo worked
for two weeks..suddenly the car felt very heavy.
it feels like i am driving with the parking brake engaged!

tyre pressure is ok. i changed the engine oil. put in new
k&n air filter. only marginal improvement. in comparison,
it feels worse than the pre-cai days.

i am baffled. what could be the problem?
my mechanic says the engine is fine.


-cheng