Hi. I have a 1991 Acura Integra LS automatic, first emission test I recorded a 2.71 Nox which failed me as the max is 2.50. I cleaned out the EGR valve and gasket and got new spark plugs (bosch double platinum). My second test I recorded a 2.51 Nox. Any tips to get it to pass? Thank you!
I am unfamiliar with emissions testing (Florida hasn’t had it in several years). I’m pretty sure EGR and your catalytic converter handles this. I assume you’re not getting a check engine light right now either. I’ve been working on EGR replacement for the automatics but it’s been very difficult. The manual versions don’t have this. 
Are there any problems with either of those systems? What about oxygen sensor?
The expensive way is to buy a new catalytic converter. The much cheaper way is to use 2 to 3 bottles of yellow isoheet. isopropyl alcohol, on less then a 1/4 gas of tank. You can buy it at Walmart or any auto parts store. It will lower the combustion temperature thus lowing your Nox. The car will feel sluggish with it. I would just fill the tank to full after emissions.
You can also retard the ignition timing a little also to help decrease Nox.
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Whoa man. I didn’t know that was a thing!
I currently have half a tank of 91 octane is that fine? Also do I need any special tools to retard the timing?
I prefer to have less then a 1/4 tank of gas just to have a higher concentration of isopropyl alcohol. I run just 87 with the non vtec engine
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Thanks for g2ic. I got the smog passing tips from reading a post here from XDeep decades ago. Been passing California smog for the last 20 plus years. Have to smog every 2 years 
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Thank you so much! In AZ we have to do it every 2 years too 
Any time my dude 
. Hope you pass. Sucks about the every 2 years part
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