a little while after putting my headers on i notice my car starting to run a little rough, when i get on it it wont let me accelerate it will start to bog down, also when i first start it up in the morning it will idle very high sometimes up to 2k then will settle back to about 1k, i know i need to put a new rear header gasket on but i dont think that is the only problem maybe a vac leak? any help would be great