Johnphilo

My wife finally bought the car of her dreams,a Mustang.. She purchased a 2000 Ford Mustang Coupe 2 door 3.8 V6 Saturday (2/7) from Lafayette, Indiana at an amazing price of $1,750.00 after talking the woman selling it down from her asking price of $2,800.00 after researching their value. Needless to say her dream car has got me stumped over two things, misfiring and her factory radio. I went to Wal-Mart the next day with it being the closest place who sold what I needed to put in a aftermarket stereo in the Mustang, but ran into something I never have with aftermarket stereos. The factory radio happens to need a Radio Replacement Interface since it is a Premium (Sound I think) and never needed a Interface on another vehicle I installed a aftermarket radio in. Wal-Mart of course sells a Interface for all vehicle models BUT Ford, she went to Scosche.Com to look up the part numbers listed on the back of the package I purchased and only one of the two had something on their sight,which was the FAI-3A. From using their other products and honestly not knowing if the part that came up after typing that in their search bar is exactly what is needed since I don't know what a Interface is for besides a headache for me nor the purpose,can anyone please help me figure this out for my wife? Second thing I don't know why her car is doing since I changed the only two things I know would cause it to misfire,which is the plugs and wires. I know they wires are hooked up right after using a second diagram due to the first one hooking them up wrong and her car not starting from it. The plugs and wires were pretty bad by some being broke,cracked,dirty and the inside of one wire was stuck to the plug under it when it was removed. Also changed the air filter,put fuel injector cleaner in the car, engine treatment,the previous owner took it into the shop when her son she bought the car for complained of it shaking and on 1-25-15 new caliper's, rotars, pads and Ignition Switch, 3 tires are about a year old,the fourth is almost 2 months old and right after the visit to the shop the previous owner took it elsewhere and got the oil changed. My wife and I saw all documentation for the work and new parts the previous owner paid for since 1-25-15, called the owners of both facilities to double check the paperwork wasn't fake and from all that being done in just a few weeks, I am clueless of what is causing her car to backfire. Also,it mainly does when she is picking up speed to go more than 50 MPH,at between 40 MPH and 50 MPH. She and I took it to Advance Auto so they could hook it up and test it and the man said it was number 3 and 4 misfiring,as well as we saw the test results. If any other Mustang owners who knows more about them, especially a 2000 Ford Mustang like hers and who loves them like she does could help my wife with her dream car I wouldn't be able to think you enough! As my wife said Sunday after finding out her radio needed a part we cant get here and her Mustang still backfiring,"Everyone has that one dream car they are in love with since a child, has the dream to own their dream car one day and I am **** proud of being able to own my first Mustang at 24 years old. I wish my grandpa was here to share the experience because with his 35+ years working at Ford by Chicago to make their vehicles, his passion and love for all vehicles that he had until death and his love for a nice,older Shelby Mustang gave me the love for Mustangs and would probably love a s**tty car if it wasn't for him. He never got the chance to own his dream car in his life and his love and passion for the Mustang and their beauty will live on through me, and my 2000 is just one of many Mustang's I am going to bust my *** to own in my lifetime." My wife has such a love and appreciation for Mustang's and with she and I both not able to fix her Mustang so it no longer backfires, has a stereo again and until she has it exactly how she wants it to be inside and out, that I am basically begging for anyone's help to get my wife's first Mustang running like a dream car should. Thank you to everyone who read this, John.

houtex

John, welcome aboard, but really... you need to break that up. It's too hard to read. You'll get more responses I'd guess.

I've responded to the misfire in the other thread you posted.

Regarding the interface, that's because the factory wiring for the radio in that car has an amplifier. So if you use the factory wiring and amp with an aftermarket head unit, you must buy the interface which will allow the factory amp to work with the head unit.

Otherwise, what you must do is run the speaker wires directly to the speakers (and/or replace the speakers) (and/or run an aftermarket amplifier)

This has to do with how much signal is being output by the head unit versus what the factory amplifier system will take in, as well as resistance and such.. it's all very strange, but yes, you'll need it in the Premium sound system cars.

Hope that helps!