I had the SES light come on and had a Malfunctioning O2 Bank 1 Sensor 1, and a Bank 1 lean. So I replaced all 4 O2s, they had 92k on them, and guess what? Same codes again. I am thinking a Vac leak somewhere.

 

Try clearing them again and see if they come back, it does sometimes happen.

If it does come back check for exhaust leaks, a Seafoam treatment is a great way to find even the little ones.

If no exhaust leak it's either the valley gasket or a slight possibility of injector o-ring. The lower inlet manifold bolts have been known to loosen over time and often just a re-torque will solve the issue. A can of carb cleaner can be a great tool for finding vac leaks.

 

Give us the exact fault code numbers so we know what failed with the 02's.
Have you cleaned all 4 connections, grease or oil will cause them to throw codes.

 

Yeah, cleaned them up, and the codes were: P130 and P171. Found a slight Exhaust leak at the Manifold flange on the drivers side. Could that be the problem?

 

Definitely and bank 1 is the LH so looks like you found the issue!! Those always leak for some reason. The good news is that it's a cheap and quick fix.... assuming you don't twist off a stud, so be careful with that.

 

Twisted off a stud. Exhaust repair kit coming up.