Originally Posted By: jongies3
I wouldn't make a habit out of it, but one OCI won't hurt anything. The high zinc and phosphorus in diesel engine oils will ruin your catalytic converter in the long run if you were to keep running it.
Please tell me how long it will take to ruin my cat? I've been using 10/40, 15/40 and 5/40 for 7 years in my '06 S2000 and it still SMOG's great, even at 130k miles. If your car doesn't leak oil past the rings or valve guides any oil you use won't hurt your cat. Now if it sucks one qt. every 1000 miles then you can shorten the life of the cat.
ROD