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2004 Nissan Altima

I have a four cylinder 2.5 SE Nissan Altima. I got the car back in April of 2008. I drove the car till October with no problems. In October I had a car audio system installed professionally. two amps, subwoofers and a power capacitor. After the stereo was installed I had a loud hissing noise. I took the car back and the shop put in two ground isolation loops. The next day my car had a check engine light on so I had the code read and it came back with a misfire so. The mechanic I took it said it was a the Number 1 coil. The said they unplugged the wires from the coil and nothing changes and they moved coils around and the problem followed. Ever since this time I can only drive the car maybe 300 miles at the most and it keeps blowing ignition coils. After about 10 coils this guy talked to a Nissan Dealer in denver and the master mechanic said it was an ECM. So the mechanic that has done all this work replaced the coil and the ECM for me and took the car to a dealer to reflash the ECM. Three days later the car died on me and found out that once again it was another coil. I have allready invested at least 3000 in the stupid car and it wont staying running right. I have suggested that it had something to do with an improper wiring on the car audio equipment. I have also tried to pursue the Lemon Law but the attorney I talked to strongly discouraged me away from this saying it would be a waste of my time and money. This car has set my wife and I so far in debt because we cant pay our bills like we used to before the car because we are always sticking at least $300 a pop to keep it running for 3 days or 300 miles. I have no clue what to do anymore. I am thinking it wasn’t a computer to begin with and have even suggested they run down wiring to see if any wires are bad and need replaced. Do you have any suggestions

I don’t think you have a car or coil problem. You may have a mechanic problem though becuase no way on earth should someone replace coils 2 or 3 times, much less 10 times.

What about the spark plugs and wires? Surely these guys should realize that either one, or both, of those items can kill a coil?

I would also point out that a misfiring coil can also kill plugs and wires, which in turn can kill a coil, which in turn…
See the point? It’s a vicious circle and if the shop has been replacing coils without doing anything about the plugs or wires then they are at fault; not the car.
Hope that helps.

Get the stereo out of there and see what happens. Seems like an easy step to take. You might find out how they are getting power to the stereo. I saw one that was wired behind the driver’s doorway. It was twist tied into the fuel pump power line which they cut for the splice. I had to fix it when the fuel pump quit. I just know they wired it into the circuit for your ignition power. That’s why it was hissing.

You had no problems with the car until you modified it by having an expensive, high-power stereo installed. The hiss was probably ignition noise, and whatever the “pros” did to fix the noise has messed up the ignition system.

Disconnect the stereo every place where it connects to the vehicle wiring system, head unit, amps, capacitor, ground isolation loops, etc, and see if the car runs correctly.

The stereo, or its improper installation, is likely to be causing the problem. This does not make the car a lemon.

I had new plugs put in right after the first coil went bad not sure about wires. I assumed that the wires were replaced with the coils since the coils appeared to be in one piece and didn’t look like they came apart. I know the plugs weren’t replaced afterwards because they never said they did any work like that. It was always coil number 1 that went bad.

Thats the first thing I did was remove the amps and the power capicator but it didn’t fix the problem. As far as the wiring goes the power source came directly from the battery and then went to the power cap and branched off to each amp. The remote power source came directly from the deck. The power supply for the after factory deck was not spliced into but the factory wiring harness adapter kit was used. The only thing I saw that was weird was the ground. The ground had like 7 little phillps head screws grounding it to the body under the back seat when I thought they should have grounded it to a much bigger headed screw that held in the seat belts or the back seat.