P01133 & p01404 pontiac

Question

Hi I have a 1999 pontiac firebird v6 that is coming up with both p01133 and p01404, it's had the p01404 for quite sometime and it has persisted through a number of the valve changes, I've been getting the p01133 for the last few months and have replaced the O2 sensor but to no change, I was wondering if this would point twords a vacuum leak as the primary suspect? If not what would I check