Hello,
I am in need of help what to check next. 99 SL1 260,000 is failing emission for NOx.
I was researching on SaturnFans.com but the site has been down for four days.

-Noted the HC is higher than normal for this car, but it still passes for HO.
Previous years this car was (GPM):
HC 0.18 CO 0.00 CO2 288.3 NOx .99
-6 months ago car got new:
PCV, TPS, MAP, idle control valve, O2 sensor, temperature sensor, ignition coil packs, spark plugs ( BKR4ESA-1) and wires, and ICU.
1st test
HC 0.59 CO 4.76 CO2 249.0 NOx 3.36
-After 1st test, I sea foamed throttle body, sea foamed gas, sea foamed crankcase, new oil change, new air filter, cleaned EGR, and put half gal 99% alcohol in 1/4 tank. 2nd test were basically no change:
2nd test
HC 0.6 CO 4.8 CO2 288.3 NOx 3.2
-After 2nd test showed no change I bought a new EGR, cleaned exhaust port from EGR to muffler (compressed air and brake cleaner). And did a quick spray down on the hoses to look for a vac leak, but didn't see anything.
Third test:
HC 0.68 CO 4.67 CO2 257.3 NOx 1.98
-Third test was much NOx improvement but still failed.

Limits
HC 0.80 CO 15.0 CO2 ---- NOx 1.50

Sorry I don't know how to convert GPM to PPM, but the general idea still applies.
----Car has no codes, (there is fraying starting on the flex pipe between manifold and cat - could this be leaking and causing my issue?)
The fact that the HC and CO2 are higher than normal tells me something is unhappy. Before I buy a new catalectic I want to eliminate everything else.

On-board monitoring:
Test $02 Data: Pass
Test $04 Data: Fail (TID: $04 CID: $20 ; Limit 512 Results 63232 (Steady State catalyst test bank 1))
Test $07 Data: Fail (TID: $07 CID: $0d ; Limit 768 Results 64256 (EGR decel test -or- Full EGR intrusive idle test MAF Out of range low))
Test $0E Data: Pass

The above to me hard to understand.
Are these results legit or is there something wrong with my software? I say that because I read somewhere that numbers could be hitting the limit in a 16-bit word if they are scaled using signed 2's (or was it 1's) complement math. If this sentence doesn't make sense then disregard.

-What should my MAP be reading (Pa)?
-Will check STFT and LTFT tonight but how should I perform this test properly? I know to look for ±10
Can I be in neutral or do I have to be driving in gear?
Should I check LTFT at a few different RPMs or at WOT?
-Anything else I could check while I'm in there?

Thanks in advance!