I have a 95 t-bird with 4.6l v8 it loops surges on right bank one fule loades bad only on right side sending o2 upsteam sensor to run lean. on take off no problems or crussing speed could this be a vaccum problem does not occour all the time my car is very very clean in side and out the engine is show room floor it also has about 600,000 miles on it very good car this is the olny problem i have ever had other than basic repair