As previously stated, you will fail the visual portion of the inspection. However, all you need to do is find a 'performance friendly' inspection station, and you should be all set. MA inspections laws on our old cars is the same as my home state, NH. Besides all of the 'regular' inspection items, like all of your lights, horn, ball joints etc. they are supposed to do a visual inspection of your emissions equipment, referencing a manual. Meaning that they are supposed to check for your smog pump, cats, full exhaust, mufflers etc. Most shops do not do that, but they would notice dumps, I would guess. So find that 'friendlier' station -- they are out there!!