meissen

My dad bought a 1995 Firebird Formula and he noticed while cleaning the engine bay that someone took the vacuum line that goes from the opti to the intake manifold, disconnected it from the opti side of the tube, and then stuck a bolt in it?

Why would anyone do that? I want to remove the bolt and shove it back onto the opti but my dad says "it's running fine the way it is, I don't want to mess with it." Is it at all possible that the opti went bad and someone put an UNVENTED opti in this car?

Z28SORR

Most likely that happened. The vented Opti. has two lines, fresh air in and vac. out. If it was a vented Opti. there would be two open fittings on it.

BTC

I don't believe an unvented opti would fit on a 95 unless there have been some modifications to the engine, such as a different camshaft. I think all 95's had vented optis, and those have a different drive mechanism than unvented optis. A more likely scenario, assuming it's even possible, is that someone put an unvented cap & rotor on the opti.

Injuneer

Correct... vented and unvented stock Opti's have a totally different drive mechanism.

Courtesy of Shoebox:

93-94:

http://shbox.com/1/93-94_opti.jpg

95-97:

http://shbox.com/1/opti_back.jpg

The vent lengthens the life of the Opti by removing ozone, caused by the high voltage discharge. It may be running fine now.... but will it run fine longer with the vent lines connected correctly?

L.O. Green95Z

I have a 95 opti with the non vented 94 cap and rotor on it. Kinda goofy but the price was right(free) and it works.