Just curious wondering whether anyone has looked into the ignition coils as for a source for just a single coil, such as a Delco D501C from a '05 Cad SRX 3.6L V6? Its hard to believe that one is forced to buy four coils to replace one defective coil esp when they can be separated!

If I remember right, GXPvenom was doing something like that.

Could Acdelco D598A Ignition Coil (12597745) from '07 CAD SRX 4.6L be a better fit for our GXP? Seems these are also sold as individual coils.

well I went ahead and ordered an aftermarket coil for a '07 CAD SRX 4.6L and will see how it compares to the GXP coils. From the photos (can be deceiving) it appears very similar and at $26.00 it not a big loss if its not the same.

Have you looked at www.rockauto.com They have a good system and show what will all work.

Had my first coil failure last week, the Caddy webs sites predict the first gen coil failure after 75K mi. Go figure I had 76K at the time. Except for the temperature outside I was some what prepared for this occurrence and had ideas where to get the coil if I should need one(or four). To get the car back on the road I picked up a Wells coil pack C1509 from Autozone @ $260
These are the second gen coils which now can be replaced individually instead of having to buy packs of four as the case with the first gen. The price each coil range from $16.00(China) to over $80 from a dealer.

The second gen coils are available individually under part numbers i.e. OEM # 12594176, ACDelco# D596A, SMP# UF564, AirTex/Wells# 5C1613, Duralast# C1556, YJ (China)# 099700-0940, AIP Electronics# U596. On ebay you can get the AIP coils for $26 each. (Note that second gen coils can not be substituted for first gen as the coil plug is different and the mounting bracket is different.)

I would add that second gen coil packs are available under part numbers i.e. ACDelco# D593A, AirTex/Wells# 5C1552, SMP# UF372, Wells# C1509.

I would add that a side benefit to replacing the coils has been improved gas mileage. Before replacing the coil I was averaging 22-24 mpg hwy. Now it has improved to 25-27 mpg. Still early to accurately pin point exact improvement but I drive the GXP 120 miles a day so it will be easy to tell soon.

Strange... but the only sign that something might be going bad was the low MPG (22-24) and randomly and intermittently there would be slight miss-fire when first started for only a couple seconds and then it would go away, the car after that would appear to run perfectly except the low mpg.

With the improved MPG the GXP may turn into a keeper for me after all

You're scaring me. I'm at 140,000. I occasional feel a momentary misfire/stumble at idle.
ACDelco D593A for $183 delivered from Amazon. A little pricey to have on the shelf, just in case.... Darn it.

You can always put the other 3 up for sale in that Forum Section.