Hello BimmerNut, its been awhile!

I recently made a move out to CA after finishing school and now that my CT registration has expired need to face the harsh reality of CA smog testing :-(

I currently have 232,000 Miles on my e34, its a 95 525i. After 9 years in my hands and almost 0 engine issues, it really doesn't owe me anything, but I would love to get another 6mo to a year out of it if I can. I have until the end of the month to get my car through smog.

I knew this was coming so I did some work that I thought may help my case in advance.
-Cleaned the air filter (its a K&N and was really dirty, I got it a lot cleaner but it may still be restriction)(<2kMiles ago)
-Changed oil(<300Miles ago)
-Changed plugs("PLATINUM+2" Bosch 4303)(<2kMiles ago)
-Changed O2 sensor (replaced with the Bosch one from Pelican Parts)(<8kMiles ago)
-Removed my chip (EAT Ultrachip)
-Ran two bottles of Guaranteed To Pass through it, ran the tank down to the emergency fuel light.
-Plugged all exhaust leaks

My car actually ran and felt better after all of this so I felt good going into the test.

I was tested today and unfortunately CA standards labeled my car as a GROSS POLLUTER

I attached an image of the failing results:

HC (PPM)
15Mph-
Max: 81
GP: 265
Meas: 305
25Mph-
Max: 46
GP: 215
Meas: 150

CO(%)
15Mph-
Max: 0.47
GP: 1.97
Meas: 0.64
25Mph-
Max: 0.44
GP: 1.94
Meas: 0.20

NO(PPM)
15Mph-
Max:683
GP:1894
Meas: 1949
25Mph-
Max:692
GP:1694
Meas:180
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Not the most encouraging results...

I drove the car hard for 40 Miles going to the smog station so everything was good an hot. It sat off for about 3 Minutes before being tested.

One thing I realized today after looking around the internet, I should have been running 87 Octane fuel during the test. I had a full tank of 91 as thats what I have been used to getting for the chip.

However I don't know if that could be responsible for the seemingly large amount of HC pollution.

Another thing that struck me as interesting is that my NO goes from being horrendous @ 15Mph to well within the limits @ 25Mph. Any ideas on why this may be?

I just ran a stomAttachment 7677p code check and got '1000' so my ECU appears to think its running fine. (My battery also died yesterday afternoon however).

At this point I am trying to figure out if I can get through this without changing the cats, and If I do need them changed, how to approach it. My exhaust is quite rusty after spending the majority of its life in the north east rust machine. It has had the flared compression joints between the cats and rear resonator and muffler replaced with welded sections, and the connection between the headers and downpipes is terrifying. Basically, I would be hesitant to dump money into welding new components into this exhaust. It also appears that many aftermarket cats may not be capable of passing in CA anyways?

With the mileage this car has on it already, I am not ready to fork out $1k for a whole new exhaust.

If I need to I would like to be able to pick up a slightly used one that I can bolt on. Anyone on here in the bay area that has a stock 525i exhaust that could part with it for a few weeks? Or know of any good junk yards around here.

I'm not sure how I would know a good used OEM cat, are there still any E34s out there with <100kMiles on them?

I am currently planning on cleaning my MAF, replacing air filter, and burning off the tank of 91 octane before filling with 87 and getting another test.

Does anybody know if its better to run with a high or low amount of fuel in the tank?
Would there be any advantage to running with the EAT chip (my intuition said no so I pulled it)
I also have an aftermarket gas cap, but I thought that would only result in evap issues.

Please help my keep my E34!

Tyler