I recently removed the blower cover on my 90 grand am to find out the air filter needed changed. I thought I hooked everything back up. The engine service soon light came on and then for the next 3 days I used up alot of gas. It also had a hard time starting, rough idle, stuff like that. Anyway, I came home one day and looked behind the cover and found a very small hard vacuum hose that was disconnected. I hooked it up, turned on the engine, no service soon light was on. I unplugged the vacuum hose and it died. So I plugged it back in and ever since then everything has been fine. However, I wanted to know exactly what was going on and how come it used up so much gas. thanks

terry

with the vacum hose off it pulled more air into the intake.
Thus needing more gas ....