imported_crXtasy

Could you guys please take a look at these results.

Car is a 93 civic hb dx 1.5L.



Limit/Reading/Result
First test:
ASM2525
HC = 82 / 34 / pass
CO% = 0.45 / 0.10 / pass
NO ppm = 636 / 860 / FAIL
RPM = 2910

Curb Idle
HC = 200 \ 41 \ pass
CO% = 1.00 \ 0.17 \ pass
RPM = 766

Second test
ASM2525
HC = 82 / 77 / pass
CO% = 0.45 / 0.37 / pass
NO ppm = 636 / 715 / FAIL
RPM = 2793

Curb Idle
HC = 200 \ 64 \ pass
CO% = 1.00 \ 0.26 \ pass
RPM = 742

Between test 1 & 2 I tried some of that Guaranteed to pass stuff. Seemed to of raised everything, except the NO. Both tests were run right after the car was warmed up and taken for a spirited drive.

What should I look to replace first?

Thanks in advance!

imported_crXtasy

bump?

imported_kIeRaN

cat

Bryce

Is the engine modified in anyway.?
What is your exhaust setup.

imported_crXtasy

car is mechanically 100% stock..

im thinking of trying a couple hundred ml of methnyl hydrate in a half tank and seeing if i can pass it.

car runs great & gets good gas mileage (40mpg consistent)

I am unsure of the age of the cat, but i was under the assumption that your cat is either working or not, and if its not your scores will be several hundred precent more than the maximum values (not just barely).

So not sure what route to go? maybe throw on a new O2? try the methanol or?

imported_honda1b6a

lol get a fake one,, haha jks dont do that

bbarbulo

iTrader: (2)

NOx emissions indicate a high combustion temp. Combustion temps are controlled with the EGR valve if your vehicle is so equipped.

Other causes for high NOx are advanced timing (retard your timing to fix it), improper fuel grade, improper spark plug heat range, lean burn condition (fouled injectors or bad fuel pressure), or improper coolant thermostat.

Check your timing, and fuel pressure before you replace the cat.

Also, another cause could be carbon fouling in the combustion chamber, causing increased cylinder pressure (effectively raising compression).

bbarbulo

iTrader: (2)

oh, also if the vehicle is so equipped, could be a bad altitude sensor or even a bad MAP.

imported_Nanase

do a real good de-carb

imported_crXtasy

pardon the ignorance, but what does a "de-carb" consist of??

imported_Nanase

You can do it yourself. There's two ways you can do it. A bottle of water, and a short vaccum hose.

Or, you can buy some chemical that cleans the injectors, like TKO.

PM me if you want to know how.