emissions testing

[ioverholt@hotmail.com (Ian Overholt)]

Others have piped in lots of good info, but there is one detail that you 
have to be certain about.  When someone says "I have a blank engine in my 
blank year car with no cat and I pass the test, no problem!", that info MAY 
NOT apply to you.  Each state has different test methods and not all states 
are even measuring the same exhaust gases or have the same limits for each 
gas.  You have to know how they will test the car (you indicated it was on a 
rolling dyno) and what gases they are measuring (CO and HC are the most 
common, but some states also measure NOx).

The reason I bring this up, is because if you have to pass a test that 
measures NOx and you don't have a cat, you cannot get the car to pass by 
simply leaning out the mixture.  When you run lean, the NOx shoots way up 
unless there's a 3-way cat there to get the NOx levels down.

Of course it does help a lot to know exactly what the emissions limits are 
for your state.  If you have not tested this car/engine combo before and 
there are a lot of stakes riding on this test (major scrutiny of engine swap 
if you fail the test) I would HIGHLY recommend doing a pre-test where they 
just run the test and give you the results without sending the results on to 
the state.  I do not know if your state allows pre tests, but CA does and 
it's a darn good thing!

If you do a pre test and you do not pass, you can then adjust the car 
however it needs to be adjusted without them scrutinizing the legality of 
your engine swap.  Pre tests cost $20 in CA.  That's my $0.02.

Ian Overholt
'88 16v

_________________________________________________________________
Send and receive Hotmail on your mobile device: http://mobile.msn.com