I have 2000 ford taurus 24 valve V6, when I drove the car on traffic light and stop sign after I stop, the engine will off, also the engine check light is on and I got codes P0171 and P0174. I tried to replace PCV valve but I could not find where located the PCV valve. Is there another reason the engine off on stop sign or on traffic light?

Thank you for your help!

Did you read the sticky from the Taurus forum Main Page at the very top titled "Codes P0171 And P0174?" In there mwt47 describes how to gain access to the PCV on a 2000 Taurus with the Duratech (24 valve) V6, just like yours.

-Rod

Click Here! (http://www.automotiveforums.com/vbulletin/showthread.php?t=768631)

yes I read that and today I removed UIM and I remove the pcv valve and I replace the new one. It's a challenge to me to replace the new pcv because hard to access for tightening the new pcv. so I don't think I am tightening good the new pcv. anyway after that, I start the engine but rough noise and I taste drive but very rough, and the brake it doesn't work. also I sow a smoke comes out from the hood I got more trouble. please advice!!!!!!

Is this roughness worse than before you replaced the PCV? Do you still have the P0171 and P0174 diagnostic codes?

It sounds like you have a big vacuum leak somewhere. Did you get all the vacuum lines reconnected, including the large one to your brake booster? Did you reuse the intake manifold gasket? Did you make sure the intake air tubing is installed correctly and securely? Did you remember to plug the MAF sensor back in?

Sounds like you had better take another look at the items that you removed to replace the PCV and make sure they're installed correctly.

-Rod

Yup, big vacuum leak. Its not that the brakes don't work its the power assist that is not working. The power assist usses vacuum from the engine to make it easier to push the brake pedal. The power booster is the big round black thing behind the master cylinder.

Thank you very much for Rod and Airjer, as you said one of the vacuum hose was disconnected behind UIM also I put a new gasket for UIM every thing is OK. you are help full appreciated.