Passing emissions test

[do2mind]

I've got a CT State emissions test coming up soon...

I barely squeaked by with the last test, so I'm thinking ahead that I might need corrective action this time, either before or after.

Does anyone know any tricks to lower CO, HC, and NOx levels? Special gasoline? Fuel injector cleaner? Drigas? Timing? Leaner fuel mix? ECU tweaks? A chip?

I'm thinking some of the above things might help "prep" the car before the test, but would actually make the test worse (i.e. fuel additives?)... but that's just my uninformed speculation... Anybody an expert in this area? No guesses please : )

I also drive quite a few miles to work... so if some of these tweaks get me better mileage in the long run, that would be a bonus. I'll give up a little power if I have to. : |

In June 2001, my emissions were tested, and the car passed with flying colors... nothing even close to the limits.
In March '05 it was tested again, and the numbers didn't look nearly as good.

I had a new engine put in the car at some point in the last few years (cracked block)... I think it was in between the 2001 and 2005 tests... which is obviously a possible reason why there's a big difference... but MORE SPECIFICALLY... WHY? I'm guessing the rebuilt engine (F22A1) is older than '93... the valve cover on the rebuilt engine was much uglier (the rebuilt one was sheet metal, the car's original one was cast... I had them swap and put the car's original cast cover on the rebuilt engine). The new engine is a tiny bit spunkier than the old one, other than that much the same.

With the new engine, if I stomp on the gas with a cold engine, or crank it way up to make a tight pass on a mountain road... it blows blue/white smoke. I'm guessing this is a ring problem... Remind me to drive to the test with a warm engine and to drive like a grandma on the way there. Could the rings alone account for the decrease on all three measures... and if so, what could I do to give the best chance of passing this upcoming test? Is there anything which "helps" ring blow-by and won't hurt me for the HC/CO/NOx numbers? More viscous oil, maybe? (I use 5W-30 now, could I say step this up to 10W-40 for the test?)

Here's the results of the two tests...

HC (limit 136ppm)
2001 - 17.1 ppm
2005 - 105 ppm

CO (limit 0.73%)
2001 - 0.14%
2005 - 0.41%

NOx (limit 1591 ppm)
2001 - 272.5 ppm
2005 - 1582 ppm [within 1/2% of the limit!]

As you can see, the figures are drastically (300% to 600%) worse for the second test on all three measures. Was the first test screwed up (are those numbers too good)?

I can't recall for sure which engine the 2005 test was done with, but something seems to be a little screwy either way, right?... if the 2005 test was on a relatively "new" refurbished engine, it should have new plugs, wires, etc. etc and be okay... but if it was still on the old engine... how did the same engine degrade so much on all three measures? I guess I need to check when I had the new engine put in.

I had a tuneup a few months ago... what will probably be 6 or 8 months before the test... should I do a tuneup for good measure before this upcoming test?

And beyond that... I'll keep my questions fairly big picture... what are the factors that affect each of these three emissions measurements? For HC and CO, I would think the main point is to get more complete combustion, correct? If not... ??? Where does NOx come from, what are the factors that increase or decrease it?

I just added a B&N cone air filter on the end of the stock intake pipe today... will this make the problem better or worse? I suppose that depends on whether the car adjusts the fuel mix depending on how much air it's sensing, or the effects of more air on some other sensor.

What do the following components have to do with anything?...

catalytic converter
EGR system

How about the other components involved in a tuneup... spark plugs, ignition wires, etc.

Thanks for any help you guys can give... I'm glad you all think this kind of stuff is fun!

[TypeG]

all you need to do is clean the egr port's. there's mention of it here:
http://www.cb7tuner.com/vbb/showthre...ight=egr+ports

or if you want an easier, but less effective way, try this:
http://www.cb7tuner.com/vbb/showthread.php?t=49352

also, drive around for a while to get the cat as hot as possible. the hotter it is the better it works. later.

[do2mind]

Thanks, G...

Both of those look like a lot of work, I'm not sure my tuner skillz are that advanced yet.

Anybody have any other thoughts? I'm thinking there's a few tweaks here and there that will allow me to squeak by until I get a little more brave on tearing stuff apart for the bigger jobs.

[Warudakumi]

A new catalytic converter works wonders too

[do2mind]

...or if you want an easier, but less effective way, try this:
http://www.cb7tuner.com/vbb/showthread.php?t=49352...

TypeG, are you saying that the less thorough way is to just clean the valve and leave the ports alone?

If so, I didn't understand that the first time, I had to wander around in the wilderness for a few days and then come back and read it again.

[TypeG]

TypeG, are you saying that the less thorough way is to just clean the valve and leave the ports alone?

yes.

as you can see, i removed the egr valve and cleaned off the carbon deposits. assuming the egr ports are not completely clogged, this will make better egr flow and your emissions will be lower. later.