Failed CA Emissions (turbo motor)

Took my 951 in for its 2 year California emissions test and failed the 25 MPH NOx test (barely passed 15MPH test). I had it tested 2 years ago, passed the test, drove it home and parked it. I have maybe 10 miles on it since then.

My readings are now:
@ 15MPH max. 1069 meas. 1066
@ 25MPH max. 669 meas. 718

Everything else is way in spec.

I drove the car some, not a lot before test.
I DID NOT put fresh gas in it.

Why would this fail NOx if it just sat for a couple of years? So for the NOx, this is mainly attributed to the Cat, right? Will monkeying with fuel (add acetone, etc) help with this?

Whattya think?

If it sat a long time with Etoh gas then I would completely drain it, add fresh gas plus 3 0z/10gal acetone and make sure your timing and plugs are good. High NOx is due to a high temp combustion and either timing is the culprit or clogged injectors can lean the mix causing high temp combustion.

To pass last time I replaced the plugs, cap, wires, O2 sensor, IAC, had injectors rebuilt by witchhunter, replaces all of the vaccuum lines with silicone, lindsey racing venturi delete, on and on and on... essentially everything related to the emissions....

Leave ethanol in a solution of long chain hydrocarbons for even 2 weeks and organic acids begin to form and jack up your fuel lines, clog injectors, deteriorate aluminum....

AH, ok. I will run through some fuel here (I just filled up with 91 after teh test). Need to add some acetone as you suggest. Will any of that stuff from the parts store work for this (guaranteed to pass stuff)?

Smell it, I bet it smells like fingernail polish remover. I run acetone every tank at that conc. just for performance and to keep the injectors clean.

WTF!!
I am looking at my results from the last time I smogged..

2009 @15MPH MAX ALLOWABLE 1125
2011 @15MPH MAX ALLOWABLE 1069

2009 @25MPH MAX ALLOWABLE 995
2011 @25MPH MAX ALLOWABLE 669

SON OF A BITCH!!

FWIW - I bought some Lucas injector cleaner that also claims to greatly reduce NOx. dumped that stuff in there with the fresh 91 and ran the piss out of the car. Took it straight to smog hot and passed.