Engine light on code p1151 on 99 mercury cougar v6 2.5l engine

what is the code your check engine light should blink when you turn key on that is your trouble code ---throwing parts at problem very rarely solves the problem the code can give you the start point towards solving problem

1. Failing MAP sensor or vacume leak on tube leading to MAP sensor.
2. Bad fuel pressure regulator.

disconnecting your battery for about 10 minutes will clear the codes but if it comes back youll need to fix the issue. in indiana pre 97 cars the check engine light wont fail you

Yes it sounds like the alternator is ready to be replaced.

Retrieve fault codes using a diagnostic scan tool. This will tell you what exactly the problem is. You either have to go to a dealer or a mechanic who has the scan tool.

have it scanned first when they pull the code they will be better able to diagnose your problem. if you are still having problems contact me with the code and i will help you....

thats when you need to get it scanned sounds like water is getting in a sencer o2 perhapes but scan it for the code it should be stored in the memory

Hold down the "trip" and "trip reset" buttons at the same time when the service engine light comes on. The service engine light comes on between 5000 and 8000 miles as an oil change reminder, however you have to reset it manually.

Disconnect the positive lead to the battery wait about 30 seconds and reconnect. This should clear the error light. Then take it out somewhere where you can floor it and go through the gears a couple times. This will establish a new acceration curve. If the light comes back on it's time to take it to a shop and plugged into a computer to see what's going on.

try changing your egr valve first