I'll post photos of the sheets when I get home... Forgive my newbness please.

What else about the car: 243,000k, headers, intake, magnaflow muffler...

This is my 2nd try, the car had been sitting almost 3 years. Gave it new ngk plugs, wires, cap and rotor, synthetic oil, mtf tranny fluid and just took it in right away. Failed only on high hydrocarbons. That was about a month ago... Also I cleaned the throttle body as it was gunked up and was sticking. I have a feeling everything in the intake is similarly gunked up.

Been driving it to work daily, (have 3 months to pass), but I noticed it leaves black soot marks from the exhaust on the driveway (congruent with high hydrocarbons right? Unburnt fuel?) also it has a gurgling type of backfire when downshifting. So I'm thinking timing.

So today I finally bought a timing gun, and it looked to be halfway between the red and white marks. (8 degrees?) I shorted out the 2 pin connector under the glovebox and set it right to the red mark. (Advanced 8
Degrees if I'm understanding the terminology)

Now no backfire, sounds smooth and drives better I think. I gave it some "spirited driving" to heat up the cat and took it in for another test.

Hydros only dropped from about 1.0 to .9, and now no2 went up also. Failed on both counts but still passed on co2.

I am assuming the cat is fouled up with tons of unburnt fuel?

So what can I test next? Temperatures on the cat? 02 sensor? I also expect due to my newbness I could be missing some really obvious stuff.

Any thoughts or advice is much appreciated. Will post results shortly.

 

Sorry, NOx (oxides of nitrogen)... Not no2. Always learning... I enjoy this stuff so much but I sure feel dumb a lot.

Anyway! This is the report a month ago where I only failed HC:



And here is the report today where (correction from above) I got worse on both HC and NOx:



June July
Hydrocarbons: 0.9799 (fail) 1.1426 (fail)
Carbon Monoxide: 5.6354 (pass) 5.1525 (pass)
Oxides of Nitrogen: 1.1771 (pass) 1.7404 (fail)

Lastly, I forgot to mention this was on a full tank of 91 octane. I've been using 91 since I've got the car, and went through about 4 tanks now. (I never siphoned out the 3 year old gas when I got the car, just tried to "balance" it with the higher octane...)

Any advice at all is much appreciated!

 

Ah. So the obvious thing I was overlooking in this case was the FAQ sticky. :/ Looks like what I need is there.

It looks clear that advancing the timing increased the NOx... And if I retard the timing somewhat that should be improved. How much I have yet to figure out... But if it was running like crap at 8 degrees, and failed miserably at 16 degrees, maybe somewhere in between, or I can just put it back where it was.

Meanwhile, I still have to get the HC down...

One thing I haven't looked into is whether it's running rich or lean... This is something I haven't gotten into before. My injectors could need cleaning? I also have not done a fuel filter change...

Car also has a K&N pod air filter... It doesn't look too bad, but I'll have to give it a proper cleaning as well.

List to do:

-fuel filter
-clean air filter
-fuel injector cleaner...
-test 02 sensor
-compression test
-pcv valve, grommet, oil change, drain plug crush washer

The only question that I'd really like to get answered at the moment is how many degrees they're talking about in the FAQ sticky when they say "retarded timing" vs "very retarded timing". (sounds a bit funny but really)