This morning a jacked up my car and oiled the shocks and springs. I cleaned my battery cables. It may be psychological, but it feels as though it is responding a lot quicker; Is it possible that it really is because of the battery cables?
How often should the spark plugs be changed, how much are basic NGK spark plugs, and am I able to replace them myself?

Also, what is the EGR valve?

 

i think the plugs should be changed every 10k 0r 15k i don't remember. But yyeah u can change them yourself it's easy.

 

lol I changed my plugs at 90K on my 94 accord and they are STILL in there with 170K on the motor. Modern SMPFI cars can go a very long time on a set of plugs. My current car a 02 CL type S won't need them till about 120K or so