03-04 which is knock sensor
07-05 which is evap control system
05-03 which is evap canister control valve

plaes tell me what these things mean - i know what the knock sensor is and how to change it but what exactly does it affect -also what exactly are the last 2 things - i have no idea what they even stand for so i cant even do anything for it until i do please help and tell me what to do and if its urgent

 

watch out you might get flammed.

please read the stickies at the top of the 4 gen page.

when you check what each code mean, also there is a detail explaination of each code and what it is and a little info to get you started of changing/repairing.

also check the how to's there is a lot of info there.

that knock sensor (assuming you change it yourself) is going to be a pain in the a**, I have had to change mine (knock on wood) but I've read its a b*tch

 

I believe the EVAP stuff is related to your gas tank. You have an evaporation canister to release excessive gas pressure in the tank. . . . simply not tightening your gas cap can trigger such codes, so check for stupid mistakes.