Check Engine Light and Brake Hissing - 1999 Solara

[gooseguy84]

Hi all, have a 1999 Solara with approx 130K miles. The check engine light came on the other day, (misfire in cylinder 1) and reset. Came back on after approx 60 miles of highway driving. Was told to look for vacuum line leaks (not sure exactly which ones). Also there appears to be a slight hissing from the brake booster area. The hissing seems to subside when the brake pedal is pressed down. Having googled and read a few topics might be the brake booster vacuum line? How do you even check it? Would these 2 things be related? Any ideas?

Thanks very much!!

[gooseguy84]

So did a quick test, with the car running, I took off the brake booster vacuum line. The hissing got worse and you could hear all the air getting sucked though the line. I put my finger over the end of the line and the hissing went away completely. I then put the line back over the brake booster and the hissing went away a little bit, but not completely. When you press the brakes the hissing does go away.

Thanks!