Jeep 4.7L (stroked) I6 engine, 5w-40 synthetic HDEO, problems with cat?

[Dark Horse]

Stroked straight six, going to run either Mobil 1 Delvac 5w40 synthetic HDEO or Delo 400 5w40 synthetic HDEO. Will this cause the high flow catalytic converter to fail, or should I not worry? Running a magnaflow hi-flow cat.

 

[Blue99]

No, no immediate problems at all.

The main issue with reduction of ZDDP levels is that the automakers were being pressured to warranty catalytic converters for 125K miles.

Some phosphorous is volatized from the crankcase oil, but most studies indicate that only a potential exists, over 125K miles, for phosphorous loading in a cat using ZDDP levels in the 1000-1200 ppm range.

 

[99]

You'll only have cat problems if the engine burns oil and even then it wouldn't matter what oil you were using because any oil in the cat will eventually kill it.