T,
Ok, just take the wires back and use the 50 bucks towards the shop test. Even if you have to take the car to a Midas shop. I understand your situation. I have a friend that wont even try to change his own oil!
I suggested to get a friend to help you put them on. Most mechanics will not install parts that you buy for several reasons. Mostly warrenty, others is money.
With your engine reving weird like that and no "check engine light" sounds strange, but I have seen stranger. Might be best to just get it to a shop and let them take a look at it. Like I said, even if it is a chain shop such as Midas or Pepboys.
Sorry to hear that you are having such a hard time. Wish you all the best.
