Where is the second temp sensor on the 2000 ford mustang 4.6?

check here...

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The best solution you'll get from books at www.reliable-store.com

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Most parts stores have a part location chart in their system and can probably help you. On most vehicles this sensor in near where the top radiator hose goes into engine. There are 2 temp sensors--hte one with one wire usually supplies the dash gauge or lamp, the one with two wires is for the ECU.

have it plugged into to see what the code is. the computer is telling you theres a problem in one of the sensors.. most auto parts stores offer this for free. hope this helps

go to most part stores and they can read the trouble code that is causing your issue most of the time its a sensor

Catalytic converter plugged ?...When was it changed last ?

ur engine is a v6, the head that has the number 1 cylinder is bank 1, so u need to go to the second head and follow the exhaust line, ull find a sensor there, probabbly has 4 cables looks a lot like a spark plug, thats ur oxygen sensor, that probabbly needs to be replaced.
hope this helps
have fun!

I replaced the coil pack to no avail. I also purchase a code reader while at the auto parts store. This device told me cylinder 3 was misfiring (P0303). I found that the spark plug wire had shorted out on the manifold sensor tubes. Replaced that wire and done.

I highly recommend keeping a code reader in your car tool kit. very useful.

It sounds like your ABS sensor needs to be re gaped and cleaned, To keep it simple, just try cleaning them first with brake parts cleaner. Your going to need two cans, one for the front wheels and one for the rear wheels. Locate the ABS sensor on the wheel hub and spray it clean as possible and see if that fixed the problem, If the the problem still there then your going to have to get a feeler gauge and re gap the sensor to the speed ring on the wheel hub. Can not recall what the gap should be but you can get that from Auto Zone or any large Auto parts store when you pick up the brake parts cleaner and feeler gauge. Good luck and keep me posted. Oh ans almost for got to inspect the wire harness at the sensor to make sure there are no damages. 

have you checked to see if the parts store lists a knock sensor for your vehicle?