I had 3 sets of after market HID's that I purchased and they were both 8k 45 watts I believe.. It didn't come with a ballast just a bulb. With that being said, I did the usual and replaced the bulbs. Once I tried testing it out, the first bulb burnt out on me instantly. Just a quick flash and that was the end of that bulb. I used another bulb and it wouldn't turn right on but then shut off within 1 minute.. So with that being said I put back on my OEM bulbs and called it a day lol..

Is it because I'm not using a better than OEM ballast?
Also is the rumor true? Is it true that IS250's only work with Garax and Phillips?

 

You are pairing a higher wattage bulb with a lower wattage ballast... I believe OEM ballasts are 35w so maybe try buying bulbs to match your OEM wattage

 

Are you sure that your car has a stock HID equipped?

 

Wattage and bulb mix should not do that. I have ran 55W ballasts on stock bulbs without any problems. You mentioned you only got the bulbs. The following is assuming your vehicle has OEM HIDs.

That leaves only 2 culprits that I can think of:

1. You bought D2S bulbs. The 2IS utilizes a D4S system, and cannot be interchanged. The turning on and then shutting off indicative of a D2S bulb being used with D4S ballast.
2. The bulbs are faulty (assuming you bought D4S). Not knocking on your purchase, it could just be that particular bulb to be faulty.

It is NOT true in my experience that you have to use Phillips or Garax bulbs with the 2IS. Although they are very reputable products, a bulb is a bulb. Electrically, they do the same thing. I have used Phillips, fake-Phillips, Osrams, Amazon no name bulbs, ebay bulbs. And they all worked without a problem. Now, the output varied quite noticeably between the Osrams and Phillips to the cheap amazon bulbs.

And I don't know much aftermarket ballasts that are better than the OEM ones. I'm sure there are, but the hassle of changing out the ballast is not fun. How do I know? Because I have retrofitted TSX projectors into my 2IS headlights, and after much thought, I decided to keep the OEM D4s (which btw is attached to the bottom of the housing) and just modify the D4S bulb itself to fit into the D2S slot. IMO, the OEM ballasts are ideal for the vehicle.