Emissions testing, passed, kinda...

[Jim Wright]

That time of year again, and as usual was worried about emissions  
testing.  I ran a tank of that Guaranteed To Pass stuff through the  
old '91, was on to a fresh tank of gas, changed the oil, cleaned the  
air filter, etc, and when the dude hooked me up to the tester I was  
blowing a reading of around 600 HC, far above the 220 I needed to  
pass.  Ugh!

Now, I was up front with the guy when I first arrived, and suggested  
he check emissions first since I've had issues with that before, and  
didn't want him wasting his time if it was going to fail right off.   
He just laughed and said that if there was a problem he'd probably be  
able to help me out, and sure enough, he did live up to that.

I wasn't watching terribly closely what he did with the testing  
system, but apparently before the test starts, it gives some info to  
make sure that it's reading correctly, that's how he knew I was over  
600 HC.  He started the test, let it run for about 15 seconds, then  
started revving the motor until it kicked out to a screen referring  
him to the owners manual.  Then he worked his magic.

He had some sort of cocktail mixed up that he poured into a container,  
with a tube that he attached to a vacuum line at the back of the  
engine, and started a slow drip.  He ran through quickly what was in  
it, but it was too early in the AM for me to remember it all, I  
remember B12, octane booster, and probably at least two other  
compounds.  He let the slow drip go for about two minutes before he  
opened up the valve on the line more and let it start flowing in  
faster.  Shortly my exhaust was blowing white smoke as it cleared the  
gunk out of my engine.  He said this was expected, and that as the  
smoke and gunk cleared from the engine, the emissions would drop, and  
as soon as the tester saw a good reading, it would kick out a pass  
result.

Sure enough, after running for about 10 minutes. the machine passed  
me, and I was on my way.  He claimed to have done this same thing on  
his cars more than once, and another worker there said his own car was  
blowing over 1000 and this got his car cleaned out enough to pass also.

So, that all being said, two questions.  First, I'm sure that what he  
ran through was probably some strong stuff, and since I usually don't  
use any additives, at about 250k miles I'm sure that there was a good  
bit of buildup there.  Any recommendations on if I should regularly  
use some fuel treatment, or try a roll my own cleaning like what this  
guy did periodically?

Second, does anyone know anything about these testing machines, and  
did I really get a good reading, or did he just fall into some way to  
trick the machine and not know any better?  All I could see was that  
it was stuck on the screen referring him to the operators manual, no  
test numbers were being shown, so I really have no idea what the  
machine was doing before it finally gave a passing reading.


Jim