I HAVE A 1999 FORD TAURUS 3.0L OHV. THE CHECK ENGINE LIGHT CAME ON I HAD IT SCANNED AND THE CODE SAID IT WAS THE CAMSHFT POSITION SENSOR. I FIXED THAT THEN THE CHECK ENGINE LIGHT CAME ON A FEW DAYS LATER. THE CODE SAID IT HAS A LARGE EVAP LEAK. I REPLACED THE GAS CAP BUT THAT WASN'T IT. WHAT CAN IT BE AND HOW CAN I FIX IT.

That is a cam sensor error. Check out all the videos on Youtube.

Go to an Autozone, Oreily, or Advance auto parts store. They will scan you car for free and can reveal the Code and possible fix.

Possibly the air sensors went out of balance when there was no fresh air. Sounds like sensors read the engine as "Lean" due to lack of Oxygen and set engine to a rich setting.

What engine? 3.0 DOHC 3.0 OHV 3.8 liter

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

need code scanner but first find what causes check engine light to turn on.you need to code scan find what code you are getting fix bad sensor.then use code scan to erase code.if you dont fix problem will check engine light will stay on.

If you have to wait to restart its usually a faulty coil or ignition module.
Someone would need to troubleshoot the ignition system when the engine fails to start to proceed. Could be a faulty relay too.

Hi, the leak is probably in your evap system. Check the cannister and hoses under the car. Repair as necessary. Also check the purge valve under the hood. Take the hoses off and see if you can blow thru the valve. If you can, it's stuck open. See if it's jammed, or clean it out with carb cleaner to see if it will close. If it will not close, replace it. Please let me know if you have any questions, and thanks for using FixYa.

The engine computer needs to be scanned, this will read a code [ such as po ### , etc.]. The codes corrospond to sensors and system affected. After the problem is fixed, the scan tool can erase the code-s and turn off the light.

The camshaft position sensor (CMP) on the 3.0L OHC (4 valve) and 3.4L SHO engines is a variable reluctance sensor that is triggered by a high point on the left-hand exhaust camshaft sprocket. The CMP sends a signal relating camshaft position back to the PCM which is used by the PCM to control engine timing.

The camshaft position sensor (CMP) on the 3.0L OHV (2 valve) engine is a single hall-effect magnetic switch that is triggered by a single vane which is driven by the camshaft. The CMP sends a signal relating camshaft position back to the PCM which is used by the PCM to control engine timing.

Hope helps.

Here is what's more than likely the problem. the cam synchronizer and sensor is bad.it is located in back of intake manifold under injector /engine harness. sensor takes a 7/32 socket to get sensor off and a 10mm socket to pull out synchronizer. The assy is like a distributor and can not be put in in any way,you will need a alignment tool to make sure engine is at TDC and synchronizer is in synchronization with cam. this will cause check engine light and intermittently running bad if at all. they are not too expensive,probably under 200.00 for both pieces. have a ford technician install,they have the right tool from ford to make sure it's aligned properly. you should be out of there for under 400.00. you can request they don't charge you diag and take a gamble by having them install just that. I am only assuming it's a 3.0 ohv. I have done several of these for this concern and this code. good luck!

P1744 is probably the TC going on the way out. :(

P 340 is probably the sensor itself. Don't get the Dorman one if it is the OHV motor.

P 401 is probably a bad DPF EGR sensor.