Almost a year has gone by without any problems or modifications on my 22 r-e...must be a world record!
But at the emissions test last week the numbers went off the chart.

The story from the beginning:
two years since the complete rebuild of the engine
Failed the first emissions test shortly after(HC value 300, 200 limit)...turned the air screw out and added 1/2 a gallon of ethanol to the tank and problem solved. Six months later did another test, with no additatives, perfect values (CO 0.0, CO2500 0.1, HC 39, Lambda 1.01)

And last week CO 1.0, CO2500 0.8, HC 999, Lambda 1.00
Both CO @2500 rpm and HC were higher than ever before...
Only mod since last time is a new EB cam shaft
New cathalytic converter, air sensor you name it.
What do you guys think???

Given the 900HC, you are either dumping a bunch of fuel, have an intake leak after the meter, you have no/little combustion in a cyl., or your cat us shot.

I would check the valves, the spark plugs(see if you are running rich), and for a vacuum or exhaust leak.

You may also want to have the O2 sensors checked/replaced depending on age. The non OBDII sensors are only good for about 80k, and tend to get lazy w/age, your ecu could be getting a false lean condition and is trying to remedy the situation by dumping fuel. Any loss in fuel economy.?

I don't think any type of additive to the fuel will reduce those numbers.

Make sure your water temp sensor wire connection is good and clean. And yes indeed, vacume leaks cause extreme havoc. Check for rpm rise while taking a propane torch with a rubber hose attached and running the end of it around the carb and intake joints. Catalytic converters lose their effectivness quicker the smaller they are.
Going thru a California smog check receintly officially makes me an Emissions Control Phd Know-It-All (completely by default, with no choice) <img src="/forums/images/graemlins/confused.gif" alt="" />!

The O2 sensor was replaced 1,5 years ago, Denso
The cat was replaced at the same time, cheap replacement but still new...
No big change in fuel consumption lately...normally it goes down a few mpg?s during the winter time.
Gotta be an air leak or some poor sensor connection then.
Will take a deep look under the hood next weekend!

My "old" cat was new less than a few thousand miles (about 4 years ago), but was cheap also, like yours, and much smaller than stock. They lose their effectivness quicker, being small, and thus don't last nearly as long as the big'uns.

You?re worring me on the cat there. if so, I guess I got what I paid for...
it was like $70, but it should last more than 5k/1,5 years even though it might be a little smaller than stock...
Was yours worn out after that short period of time?

Well, all I know is, the tech who ran the test (who I really trust) had me do every possible improvement, adjustment, tune-up, etc before replacing the cat, and it didn't pass. Installed a new cat and it did. It didn't look that bad, looking through it, but, it wasn't doing a good enough job.
So, make sure all plugs are clean, gapped right, and firing with no missing. Clean up those distributor cap towers (internal and external) and rotor. Check the timing. Look for leaks in the exhaust as well as the intake. Change your oil just prior to testing, and make it a heavy straight weight to reduce burning. It all worked for me.
Good luck.

Echoing Snowtoy, check valve clearances.

Put in a new cap and rotor a couple of weeks ago.
Gonna check the valve clearence, haven't re-checked since I put the new cam shaft in last fall.
Will also put new plugs in and change oil and filter, time for the spring overhaul soon anyways
And ofcourse check all connectors, intake for air leaks, exhaust system for leaks and see where that leaves me. Hopefully I dont have to get a new cat. It came w/o flanges so I had to weld on the old ones.
Thanks <img src="/forums/images/graemlins/cheers.gif" alt="" />

On another forum we were discussing the smog fail issue w/the higher flowing cats. Since the higher flowing cats move exhaust gases more efficiently they need to operate at a much hotter temps to catalyze. Often when idling the higher flowing cats aren't hot enough, which sitting and waiting at a smog shop is usually the norm. However w/your HC's at 999, it isn't likely that the cat isn't getting hot enough, it is more likely that the cat is shot, or you are dumping a large amount of unburnt fuel into the exhaust system. You should pull the cat and see if it burnt out, it could have been bad from the start. If it looks god, have the shop test the exhaust gasses prior to the cat, if they aren't double, the cat isn't doing its job. If they readings are much higher than you have an issue somewhere else.

You said the O2 sensors were replaced using Denso's, were they oem plug ins, or were they universals that you spliced in.? If spliced you can often change the readings the ecu receives due to longer wires or more resistance.