Need help with 458 o2 sensor CEL and aftermarket exhaust

I have been having an ongoing issue with the 458 and a check engine light. Here is the scenario.
My 458 has Fabspeed headers, sport cats, and a S-line cat back exhaust that I installed later on.

When I took delivery in January of 2018 I wasn’t really driving the car because it was winter. I installed my exhaust around April. As time went on, I started getting: "Catalyst temp not plausible", see dealer on the LFT. The code on the scanner says- P2097 Post catalyst fuel trim system too rich bank 1.

I bought a scan tool luckily and was able to clear the codes. However, it should be known that after this light has appeared, if I continue to drive 10-30 miles, an Check engine light will stay on, and the car will go into limp mode until I clear it. This issue over time has increased in frequency. It has come on as much as 3 times in a 40-50 mile drive. Note* I have put about 2800 miles in the car since purchase. Current miles is about 9300

My technician and I assumed over this time that the aftermarket sport cats were affecting the o2 sensors. I installed o2 extenders hoping this would correct the issue. It did not. So then we said, perhaps the o2 sensor is actually bad. I installed a OEM one yesterday on bank 1 (pass side) and it made no difference.

This issue is now becoming a significant burden to my enjoyment of the car. More importantly, I keep having to clear the code thus the ECU is not “ready” so I can’t get the car inspected. It appears my only options at this time is to either tune the car, which I’m reluctant to do and it’s a significant cost. Or return it to stock exhaust setup.

To my automotive knowledge, while the timing of installing a cat back exhaust is coincidence that this issue became present, the cat back is exhaust is AFTER the o2 sensors so I cannot understand how that would affect it.

Any advice or insight? Has anyone dealt with this after installing exhaust components?

Thank you

 

I will take that into consideration, but I do not have a P0420 code. Plus every time it's the same bank and same code. I just can't see how straight piping AFTER the sensor would affect this...Unless, could a change in back pressure affect the sensor?

Thats what I was thinking. What is irritating is that I bought the car CPO and I was not told it had the headers and sports cats. I only found out while installing the cat back system. While it was a $9000 gift, it's not what I would have wanted to do to the car for the very reason of when you start messing with headers and cats, you need a tune or other bugs can come out.

Yes, I keep it on a tender.