02 530i P0430 (P1349 & P1351 Pending)

[NoClue]

Greetings everyone. I would appreciate some help with trying to figure out what the issue is.
I purchased the 2002 530i in the beginning of November 2017 with 183K miles on it, interior and exterior are in fair to good condition.
In the beginning of December 2017 I had P0171 (System Too Lean Bank 1) & P0174 (System To Lean Bank 2), I took to an indy (didn't have time to diagnose or fix myself) and they determined it was the DISA valve, was replaced with OEM parts.
About 10 days ago, the CEL came back on, the MPG dropped massively, was at about 15 MPG, so I drove home from work and used the codereader, and then this past week I have been too busy to worry about it and have been able to borrow a 1999 Crown Victoria from a family member. The current code is P0430 (Catalyst System Efficiency Below Threshold Bank 2) and the pending codes are P1349 (Misfire Cylinder 4 With Fuel Cut-Off) & P1351 (Misfire Cylinder 5 With Fuel Cut-Off).
Is my cat or post cat o2 sensor bad then, or am I looking at something worse since it does have pending misfire?
Any help would be appreciated, as I would like to be able to know what the issue is before I take it somewhere and have them tell me what the issue is, where I live there is 1 indy euro specialist and 1 BMW dealership and with either of those labor rates (and trickery) I would like to be informed before they "inform" me of what the issue is. Thanks.

[edjack]

Sounds like a clogged cat on bank 2. That could cause a misfire.

Has the performance dropped off?

[NoClue]

Since the CEL came on I haven't driven it, but I do believe the performance dropped slightly.