It will be impossible to give you any better than a broad answer here, because there are literally hundreds of possibilities as to why a check engine light(CEL) comes on. The system would have to be scanned to retrieve whatever fail codes there are. Then, we would use a manual (that is literally 3 inches thick)that contains flow charts with pinpoint tests, using a voltmeter, to hand diagnose, and find out what is wrong. This process can take a few minutes, it may take a couple of hours, depending on what is actually wrong.
Now here is the "why" of a CEL: What is actually turning on the CEL is the Powertrain Control Module(PCM), commonly known as the engine control computer. Inside of a PCM there are actually two separate systems. One is control, the other system is diagnostics. PCM diagnostics acts as "big brother," constantly looking over the shoulder of the control side of the PCM. Diagnostics is constantly monitering systems to see if the expected voltages and values are present. For example: If the PCM diagnostics knows that it has been so many minutes since the engine was first started, then the engine temperature should be around 195 degrees. In our senerio, if the engine is still 160 degrees, it sees a problem, and sets the CEL. The technician has to use pinpoint diagnostics to see if we have a stuck thermostat, if the Engine Coolant Temp(ECT) sensor if sending a false signal, if the wiring between the ECT and the PCM is bad, or if the PCM is faulty and interpreting the signal received from the ECT incorrectly. But the PCM is not capable of monitering everything all at once, so it basically goes down a checklist, over and over again, as you are driving down the road. Sometimes a problem can come and go intermittantly, at the right times so as to avoid detection by the PCM. That is why sometimes a CEL doesn't always come on everytime there is a problem. Sometimes you can unplug a sensor even while the car is running, and it takes a while for the CEL to come on, just because the PCM diagnostics hasen't gotten back around to looking at that area yet.
Our senerio only talked about one area that a PCM moniters. There are dozens of sub-systems that the PCM looks at, and dozens of possible failures within each of those sub-systems, that could cause a CEL.
Upstream sensor located by engine,or downstream sensor in exhaust under car ,or if blinking ,possible catalytic converter failure
Could be many reasons. Have the codes read, they will help lead you to the problem. Most auto parts stores will read the codes for you for zip.
If the light has come on the system has a problem and set a code(s). Most auto parts stores can read the code(s) and tell you what went wrong.
P1443 Evaporative Emission Control System - Vacuum System - Purge Control Solenoid or Purge Control Valve fault Loose or defective gas cap will cause this code.
what will cause a Ford Taurus 1998 24 valve to overheat
Check fuses. They both could have the same fuse.
There are several things that can cause your 2002 Ford Taurus to hesitate when accelerating. A dirty air filter will cause the problem.
Check engine light? Usually indicates a problem in the emission control system - have vehicle scanned to determine the problem
No.
from what i gather from my book it to do with emission system i only know cause i been looking all over net as to why mine wont start and my check engine light is flashing not staying on
A bad/clogged EGR or pcv valve can cause a motor to shutter, idle erratically, hesitate and/or stumble on acceleration and have decreased performance. Some emission control systems can be sensitive enough that it in theory could happen. W/ some nissans and hyundais a oil fill cap or fuel tank cap that is left off will cause a motor to die. I have personally experienced it w/ a 91 Nissan stanza and a 06 sonata.
My 98 ford Taurus jumps while idlingidling