If the 'check engine' light came on in a 2000 Ford Focus and the car stalls at idle when warm what might be wrong?

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There is a vacuum hose between the firewall and the back of the motor, it is formed with the 2 ends different diameters. The hose collapses when it is running which causes the engine to stall. I believe this is a dealer only item. Just replaced mine and the car runs fine now.

Answer

Take it to auto zone and have the codes read for free.

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its just a vacuum hose probably. mine did it before too.

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Autozone will not provide enough help.

Pull the codes from the computer, match the code to the troubleshooting procedure, follow the procedure to find the source. Repair the source, light will go out if that was the only problem. There are "monitors" or self tests the computer runs the car through a drive cycle, if a problem occurs, it may not run all of the self tests until that problem is taken care. Therefore, another problem may exist. It is emission related. OR hook up a scanner that is capable of clearing codes, and hope that none are still active.

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Check that the Oxygen sensors are correctly installed and working. Also check with your ford dealership to see if your car is one of many that needs a new FUEL pump. Ford has a TSB on this and will replace it for free... I have a 2003 Focus SVT with all the same problems.

Answer

could be a PCV Valve. My 01' Ford Escort with similar engine needed that recently. Appox 5 dollars easy fix.

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My 2000 Focus wagon had the exact same problem and I could hear vacuum sucking in the engine compartment. In the end it was two failures at once: 1) the PCV hose failure like everyone else, and 2) a broken white plastic vacuum cap on the intake manifold.

Some folks have luck simply replacing the odd-sized PCV hose with the Ford replacement, but I was not so lucky. In my case both ends of the PCV line (under the intake manifold and connected to the PCV valve) were bust. So, to replace the entire assembly I did the following:

I bought a "PCV elbow" (by Help! auto parts), hose clamps, 3 feet of 7/16" fuel line, and a replacement PCV valve all from Pep Boys. I bought a 1/2" brass hose connector from Lowe's. I connected the elbow to the fuel line with the brass connector and secured the PCV valve in the other end of the fuel line with a hose clamp. I removed the old hoses and PCV valve and replaced them with the new rig. I had to route the new hose around the engine block, but there was plenty of room.

I still had vacuum leaking and a really rough idle after replacing the PCV line. I found the source of the leak by using a length of hose as a stethoscope. It was a rotten, white plastic cap on the intake manifold. I bought a set of rubber vacuum plugs (by Help! auto parts) from Pep Boys and one was a perfect fit.

After both of these fixes the idle was back to where it was a couple of years ago. Good luck!

First answer by Joe JOhns. Last edit by Kevintabb. Contributor trust: 7 [recommend contributor]. Question popularity: 121 [recommend question]