I've heard of many tricks to pass emissions, anyone heard of any sure fire ways of passing? I have a gsr swap in my 93 si with no cat. Is it possible to just lean it way out? I have a FPR so it wouldnt be hard to lower the fuel pressure before the test, then raise it back up after. I have to take emissions in a month or two and I dont feel like redoing my exhaust right now. Any other suggestions? I know its not really environmentally friendly but I feel i'm doing my part already. cat or not, my car gets still gets 30mpg.

 

I know you're not going to like this suggestion, but... get a cat. You'll lose a negligible amount of power, your car will be quieter, and it'll laugh off the sniffer.

An easy "trick" is to slightly retard your ignition timing. Leaning it out might reduce HC emissions, but I bet the additional heat will cause NOx emissions to rise. Also, make sure you're all caught up on general maintenance.

If worse comes to worse and you still refuse to buy a cat, you can run a mixture of pump gas and methanol/ethanol. I'm not advocating this "trick", but the mixture will burn much cleaner, and you should pass. However, once you do pass, get the alcohol out of the tank ASAP.

 

ill try retarding the timing, how bad is it to run the car really lean for a few minutes though? do you think 30psi fuel press. and retarding ignition timing to about 14 degrees btdc would do the trick?

otherwise, I guess im on a hunt for a 2.5" cat, thanks for your help!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by N1 Andy &raquo;</TD></TR><TR><TD CLASS="quote">ill try retarding the timing, how bad is it to run the car really lean for a few minutes though? do you think 30psi fuel press. and retarding ignition timing to about 14 degrees btdc would do the trick?

otherwise, I guess im on a hunt for a 2.5" cat, thanks for your help!</TD></TR></TABLE>
I wouldn't suggest tampering with the fpr at all. If you're going to do that, leave it to somebody who know what they're doing (no offense). If you encounter bad preignition, you'll have to worry about a lot more than just an emissions test.

Good luck.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by N1 Andy &raquo;</TD></TR><TR><TD CLASS="quote">ill try retarding the timing, how bad is it to run the car really lean for a few minutes though? do you think 30psi fuel press. and retarding ignition timing to about 14 degrees btdc would do the trick?

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Too lean and you'll get what they call "lean misfire." That will cause the HC's and O2 levels in your exhaust to go up. Combustion efficiency goes down as well, i think that one is CO2? My last emissions course was a loong time ago, lol.

Anyways, your timing at 14 degrees is on the low side, but still within spec.

Ultimately, you will probably need a cat.

 

dont adjust ur fpr to 30psi ur asking for trouble, sounds like u really dont know what your doing

 

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by quicksilver1689 &raquo;</TD></TR><TR><TD CLASS="quote">dont adjust ur fpr to 30psi ur asking for trouble, sounds like u really dont know what your doing</TD></TR></TABLE>

In terms of passing an emissions test without a cat? you are correct I don't know what I'm doing, why do you think I made a post here about it. Thanks for the help anyways