my 2000 (3.1 6 cyl) grand prix recently started displaying an emission code and first glance under the hood revealed some disconnected pvc tubing. i reattached it but think some of the rubber boots have just had it (car rolled 200,000 on the odometer in January!) and need replacing. i can't find the moulded "plastic" tubing that runs from the top of the engine to the back. any suggestions?