I have been getting P2098 code I did have an exhaust leak got it fixed reset the code but it came back within 50-100 miles I'm running Z1 hfc also but had it on a year without issue could it be those throwing the code or something else ?

 

I was told it is common thing with test pipes, and hi-flow cats

 

It's also very possible that there's excessive carbon build-up or that it's on the way out. See if you can data log and observe voltage readings. I'm currently trying to troubleshoot mine recurring P2098 that comes up after 300 miles

 

swapped the 2 downstream o2 sensors and code went away