Okay, I have had damn idle issues (which the idle will stay around 1500 rpm for about 20 seconds after I get off the gas. also the idle gets worst when the a/c is turned on or the defroster) and a check engine light on for about two months now. I have replaced all of the following parts that did eliminate the check engine light but not the idle problem.
1 DPFE
2. TPS
3. MAF
4. All vacuum lines leading to the DPFE
5. IACV
So tonight after dinner I started in on the focus. I cleaned the throttle body and linkage thinking that might be the problem. Then I noticed as I was revving up the engine that this Vacuum line kept collapsing each time I would rev the engine. Could this be the source of my idle problem and what the hell is this vacuum line for anyways? Any help would be great thanks.