2001 Focus Idle Problem

Really rough Idle on the focus surges really bad, and doesnt run well under load. On hills car feels like it loses all power and takes good minute to regain power. Have read other threads, possible coil replace, or value job needed? Took it to AAMCO and had rear mount replaced, still has some shaking when under load, dont know if it is tied with bad mounts or idle problem. Please help me out. Dont need this one to die on me daily driver.

Check the PCV valve elbow at the intake plenum. What you are describing sounds like a vacuum line could have reptured or come off a vacuum connection. Also, a stuck EGR valve could produce this symptom, but it should also set a code with the OBDll system. Are you getting a CEL?

The engine stumbling under a load is the classic symptom of plug wires grounding out. If you haven't replaced them yet change the plugs and wires. This, too, should set a misfire code on the OBDll diagnostic system. Even if you are not getting a code plugs and wires will increase your gas mileage and make it run smoother with more power. NGK V power plugs are good. They are resistor and have a low quench area like the more expensive plugs at a standard plug price. Low quench area keeps the spark hotter. It's the heat of the spark, not the spark itself that ignites the fuel.