Mac Dumps are they Street Legal in Mass.?

Are they not legal come inspection time because they can't do the sniffer test or just not legal period?

Mass no longer has a sniffer test for ODB1 cars, pretty much any modification to your car is illegal in this junk state. Ive gotten a sticker with a 3" exhaust and dumps. Didnt have to pay anyone extra, and it wasnt a "favor" to get the sticker. You just have to go to a place that is into cars and if your cars not a ****box and all the safety equipment is there they will pass you
 
Technically not legal because your exhaust pipes must exit rear pf passenger compartment. The trunk is considered part of that. So you would fail a visual.

However, unless you are an a hole, and draw tons of attention to yourself, you should be fine.

As for inspection, with these cars it's nice to find a shop that is mustang friendly.
 
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!!