Okay, so our limits are..

HC, .80gpm
CO, 15.0gpm

That's all they test for here.

First time I went in...
HC, 2.34gpm
CO, 44.6gpm

I belive my car was running in limp-home mode that day and i had original plugs and wires. Man were those plugs bad.

Since then, I've regapped the plugs, installed 8.5mm wires, and a new 3" Catco cat. Besides that, all that's changed was the K&N.

Went in for testing today and barely failed.
HC, .98gpm
CO, .1gpm

So now my CO is about non-existent (why did this drop so much?) and my HCs are much lower, but not quite there yet.

I only have one more chance at passing they say before I have to talk with "the office". Should I bump the timing a tad, run 91+ octane gas, and add a bit of alcohol? The engine temp was between 180 and 195 or so. I have the stock T-stat to my knowledge, but this weather just makes it hard to get the temps up much. While driving, the temps dropped to 177 or so, so I threw it in neutral and held the RPMs at about 1500rpm while I was waiting in line.

What are some tips to bring my HCs down from .98 to .80?

 

What is your base timing set at? A few degrees really increases the HC's. Also, is your EGR up to snuff?

 

EGR doesn't affect HCs. We don't test for NOx here. Nevertheless, yes the EGR works.

My timing is at 6* (stock) and the entire timing table in the PROM is also stock. I was under the impression that more timing lowered HCs/CO and increased NOx, no? I thought advanced timing had somewhat similar effects as more compression. Gives the mixture more time to burn before exhaust valve opening.

 

I goofed and was confusing this with NOx. Sorry bout that. HC's are due to incomplete combustion and the unburnt fuel in the exhaust is measured. How warm was your car when it was tested? How many miles are on your motor? Cabron depsosits and exhaust valve leakage are a few of the culprits for high HC's on older engines. Does your motor consume any oil?

 

Replace the O2 sensor. It can be weak w/o setting a trouble code.

Change the oil before you go back as well. People scoff at that, but it does help.

 

Yeah my oil does need to be changed, just in time for the colder weather. I actually have a new O2 sensor sitting in my garage that I attempted to install the other day but could barely move the old one. I'll get aruond to doing that this weekend hopefully I guess.

 

If we're slow at work tonight, I'll try to hook up a scanner to one of the computers and scan in my emissions sheet and bring the file home to post up. The HCs are just barely over the limit at lower speeds (~40) and over that the HCs are low. They do pop up to 3 for about 10 seconds when the car is decelerating though. Maybe I could mess with the DFCO settings in the chip a bit more. That run was with the stock chip.

 

like stated by five7kid it sounds like you are running just a teensy bit rich. Your 02 sensor (there's a socket tool for removing O2's that that with a breaker bar will make life SO much easier), or your Coolant Temperature Sensor could be sending weak signals and dumping in too much extra fuel.