dgibs

After installing a Eurocharged tune, my 03 CL600 began misfiring on cylinders 1 and 9 along with a code for "random/multiple cylinder misfires detected". I'm assuming the codes are correct and I need to have both coil packs repaired as 1 and 9 are on different modules. Does the 3rd code indicate the control module for the coils has an issue?
I'd love to have a permanent fix in the form of a lifetime warranty. I saw in another m275 related thread that BWD was offering a lifetime warranty, but I checked their site today and their offering has been reduced to a 6 month warranty..
What would you guys do in my situation? Any insight would be greatly appreciated.

Dr Matt

Most of the old coils fail within a short time after a tune, so if you are still on 13 year old coils I'd start by replacing both coils and adding a fresh set of spark plugs while you are at it. If you don't, you are just postponing the inevitable. I haven't seen any people complain about the newer coils failing so I think you should be good for a decade or so. If you are still having misfire issues, you can replace the module later, but I bet you will be fine with just a set of coils and plugs.

dgibs

I changed the spark plugs and plug boots right before installing the tune, so those should be good. Do you think having the original coils remanufactured would also be a good option? new coils are so pricey..

Turboaction

Look at the warranty on the rebuilt coils. I repaired mine myself and it lasted about as long as the warranty period before developing additional issues. I'd just buy a new coil pack... you can get them for under $1000 from Autozone if you order them online with the 20% discount. The right side has a lifetime warranty, and the driver's side has a 2 year warranty. They're both the new revision of the Temic OEM coil packs.

Mik30

I experienced the same issue of my original coil packs failure immediately after installing tune. I replaced with brand new units (780 & 680 new part numbers) and no issues since. (also found that Autozone "Duralast" no longer carry the coil packs even though they are shown on the web site).

ZephTheChef

I bought mine from FCP Euro. They were a little more expensive than some of the auto parts stores, but FCP puts a lifetime warranty on anything they sell and they have always been top notch when I have a question or problem. Also, everything drop ships direct from Mercedes-Benz USA so there's no doubt you're getting genuine parts.

For what it's worth, mine also failed shortly after a tune. Don't know if they mess with the dwell or if just the higher cylinder pressures put more stress on the coils.