Originally Posted by uberxfire2
I wanted to give everyone a follow-up to my recent flirt with disaster. As I posted, my CPS went out (intermittently) about 2 weekends ago. After ordering a part online from RockAuto, I decided not to wait and bought one quickly from Autozone (local) and had it installed by TireKingdom ($57 +$94 install). That part failed the next day. The online part ($42.00 + $18) came in two days later. I installed that one myself in 10 minutes, but after 2 days, that one failed too. Both were manufactured in Taiwan.
After scrambling my brain, you all put me at ease and said it was probably bad parts, not a more serious issue. So I bought the Bosch part from German Auto Supply, Ltd. ($47.50 + 30 to overnight). This one took 15 minutes to install because it has small 'ribs' down the tube and if you don't put it in straight, you can't rotate it to get the bolt hole lined up.
It's been 3 days now and not even a hiccup when I get into it! Mercedes engineering and tight tolerances require that you buy quality parts. If I would have done that from the beginning, I would have saved over $200 and 9 days of heartache. Moral of the story: Buy OEM parts! Saving 10-20% will cost you 100-200% in the long run. (oh - and listen to the guys on this forum - they DO know what they're talking about)
Thanks for posting up your findings! This only further confirms that Bosch is really the only way to go for the CPS. Prior to all the reading on this forum I honestly would not have given buying an aftermarket replacement a second thought (I didn't on my Limited). I am updating the original post if I can with this information.