I have a 01 Taurus SEL V6 DOHC 123,000 miles. I have had a bad egr valve for a while now. Was told not to worry about it since we don't have emissions here. The other day engine light started flashing and engine started "jerking" whether we are idol or moving. Had codes pulled and came up misfire in cylinder 1. And the faulty EGR. So I changed all the plugs and wires. Checked all fluids. Not better. In fact it is worse. Now my exhaust makes a loud "puh puh" when we apply the gas and the engine still jerking. Car also stalls out if we don't keep foot on gas. Seems to be a hissingish sound coming from somewhere under hood. Sounds like air being sucked in. Could my EGR valve be causing this problem? What else should I look for?