2 points hydrocarbons..im hoping my cats arent failing.

post the complete report, it'll be more helpful.

More likely in need of a tuneup if it didn't fail by much.

tuned it up about 20,000 miles ago with all parts from the dealer. im bringing it back in the morning and will pull it in right off the freeway.

Make sure you have a good ECT, and the O2 sensors are doing their thing, you need a nice real time info scan tool to check things better if you don't pass this time.

The $117 one will do live data, and of course its for OBD2 that means from 95 on up in the LS line. These are not top of the line scan tools that are 2 way and can turn on and off sensors and systems to check them, but for the money they do a lot.
https://actron.com/products/field_ca...diagnostics-53
I have an older actron and it works good.

This is the one I'd go for if I was going to get one.
https://actron.com/content/autoscann...a-color-screen

If really close on the emissions test; Before retest; check thermostat and, or, replace ECT sensor, Select a no wait day or location, Drive at highway speed for 30 minutes, (engine and cats nice and hot) remove air cleaner a block away from test facility, have all power accessories off.

thanks for the replies..ill post when its done. i had already put some cataclean in this last tank. im changing the oil and making sure it goes on the test when i pull off the freeway

+1 on the ECT if it has high miles. O2 sensors is a possibility, I feel the ECT will bring the main gains all else checked like the tune, ignition and such. A 51 or 35 is pretty high in the HC range. I looked at ours for the past 6 years, the measured 15 and 25 MPH:

2010 - 1,1
2012 - 21, 2
2014 - 5, 5

During '13 the caps, ECT and 70% of the vacuum lines were changed out. CO went to 0 in '14.

I'm a bit concerned about this year's NO reading so the EGR is on my list of items to check.

good idea about testing after a freeway run. cats work best when up to temp. even ask the tech if he can hold the revs of the car for a minute prior to starting the test. also make sure the car is properly warmed up (coolant up to temp), where the electric fans turn on when at idle for too long.

What octane fuel are you using?

Premimium is available 91 or 93 octane. The ECU will retard or advance ignition timing, and enrichen or lean fuel mixture to avoid detonation based on octane.

If using 91 see if the extra 2 octane points makes a difference.

I can tell who is using 87 octane by carbon build-up in throttle body...

Do you have available 100% gasoline vs.Gasahol (10%)?

Mileage will improve due to higher heat content of 100% gasoline whiich suggests a cleaner burning engine(from an emmissions standpoint).

In Chicago we have summer and winter blends... which is your station dispensing?

Are you using Shell or BP?

What type of oil do you use?

I have read that synthetics offer highway MPG advantages . I use 0W 30 syththetic (instead of 5W 30) and the engine starts effortlessly cold. Perhaps less H.P. for oil pump benefits emissions

This before doing anything else.

91 octane..chevron
10% elthanol
summer blend im sure
i am using mobile 1 10w-30

So did it pass this last time?

Try using 93 octane to see if that helps. The ECU may advance the timing a hair and adjust fuel mixture to a more favorable emissions test.

Try using 5W 30 ynthetic.

5W-30 ? Why is that going to help the rings seal better? I think not.

i take it in first thing tomorrow morning..i had to reschedule it so i could put it right on the machine when i arrived. i can only get 93 octane through octane boosters or at infineon raceway...sonoco fuel