I have a problem in MW2 I usually play in ESL lobbys and u know so many tricks and shooting thru walls so i have been trying shooting thru walls and I get FPS drop not its no small I play at 1024x768 everything off except for ragdoll and bullet impact and texture quality automatic i tried to lower to 800x600 or 640x480 but i still get those FPS drop i turned off brass and blood tried using some FPS config file still the same and I have updated my driver and the same BTW here are my PC spec:
Intel i5-2300 CPU @2.80 GHz 4 CPU's
With those specs, you shouldn't need to use a fps config, or even lower your resolution that low. Do you exit out of all programs before running the game? Do you use Game Booster + Ccleaner + Advanced System Care? Also check your computer for viruses.
The problem might also reside in this question. Are you running a x64 OS or x86 OS? Many 64-bit OSes use a base amount of RAM nearing 2GB, Plus programs in the background and then good Ol MW2 might be using his RAM nearly all the way up.
Also, Does your case have sufficient cooling? If the card can't breath and is overheating you can get major fps loss