Smog Issue

We have found on the older vehicles that are run on the rollers it makes a difference of which test center tests it. Have been told by former tester there is a certain technique that if the tester does not know or wont use the vehicle will probably fail. We had an older vehicle that failed the test, the tester actually told us "of course it failed it is old". The shop we took it to could not find anything wrong and suggested we take it to another location and we did and it passed. IMHO check out different test locations and find one that is in area with a high number of older cars in there area they probably know the technique to get it to pass.