I bought my 87 bird about two months ago. I have recently put on a K&N e-0773 filter. I at first rerouted some of the hoses in my Charcoal canister and I relocated the IAT to the fender well. Now the car is getting about 5 miles to the gallon. I cant smell gas at all and the car is running like a champ. before i made any changes the car was getting about 15 mpg and it was idling really rough and would stall alot. After the changes the idle/stall issue was gone and only the mpg suffered. no ses lights or anything. can someone tell me how to get this car back to being affordable to drive. please!!!!

 

Did you mess with your egr at all? What about your cat? Could be either one. A k&n wouldn't affect the mpg THAT much. Try putting the hoses back the way they were with new hose. Also it might be a very small injector leak. My bet would be bad egr. A clogged cat would make it drive a steaming pile of ford.