Replacing the Catallytic Converter

[lucentedg]

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From the pictures you can tell the Cam Seal once old is prone to leak or failure. Octane will cause pre-ignition or pinging when under load as in up a hill. Driving it hard and age has more to do with it than Octane.
Blessings,
BKM
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When I replaced it, I also replaced the breather box. Now I am running full synthetic in it. My mechanic said the tubes around the breather box were 50% blocked and the synthetic would help to keep that from recurring. 50% does not seem like much blockage. I really hope this does not recur.

[steve850]

Wow, this is s multi-topic'd-post not sure i can follow the whole thing, lol. For the crankcase pressure seal blowing issue,
When you replaced the breather did you get ALL the related tubes and hoses cleaned out? These cars can get sludgy pretty quick. If the whole pcv system was changed/cleanef I would seafom it well and run good synthetic. Not all synthetics are created equal. Do a periodic crankcase vent check when hot for piece of mind but you should be good for another 100k if you can keep the sludge dowm

I always run my volvos on at least 89 octane (canadian calculation methods may not be the same, because i know any old chevy junker that runs on regular up here will ping like mad in the states...)