Danger: RESISTOR SPARK PLUGS???
 

related to this post http://www.peachparts.com/shopforum/showthread.php?t=197392


we just had an issue with a customer a few weeks ago, for what we had we were dealing with bosch plug FR8DPP33, one of the techs here was diagnosing a rough idle for a 112 V-6 engine, the rought idle was obvious, but not enough to set a misfire code, when he checked the plug number installed in the car it was F8DPP33, knowing that through bosch all that was available to the aftermarket was FR8DPP33 he assumed that someone had previously installed incorrect plugs, so he recommended to replace them with the FR8DPP33, once that was done, the rough idle was obviously still there, and he told us that mercedes had installed the set of plugs, so we did some checking and found that untill the supply of the FR8DPP33 plugs were exhausted mercedes was the only one who sold them, so we began ordering all our plugs from mercedes directly instead of worldpac, we wanted to install same as what dealer was using, i guess their supply ran out because about 4 weeks later we started getting the FR8DPP33 plugs from mercedes, due to the higher cost from mercedes we started getting them from worldpac again. so the R plugs will be replacing the NR plugs for some applications. by the way, the rough idle was caused by defective plug wires, replacing all 12 soved the rough idle issue.

below are some examples directly from a bosch chart
Old#- Replaced by
F7KTCR - FR7KTC
F8KTCR-FR8KTC
H8DC AND H8DCO-HR8DC+ (YTTRIUM ADDED*)
H9DC AND H9DCO-HR9DC
W7DC AND W7DCO-WR7DC+ (YTTRIUM ADDED*)
W8DC AND W8DCO-WR8CD+ (YTTRIUM ADDED*)
W9DC-WR9DC
W9DCO-WR9CD+ (YTTRIUM ADDED*)
F8DPP33-FR8DPP33

*http://en.wikipedia.org/wiki/Yttrium

I don't know what the "DANGER" is related to either?????

Resistor plugs are fine on 99.9% of all MB applications.

i agree hence the ???