jesus jimenez

honda tech memebers please help because i don't know what to do. I try passing the emissions test the first time but failed since i had a test pipe,so i try 2 days later with a magnaflow direct fit catalytic converter and it failoed at low speed (HC standard is 153 - reading 176 ) (NOX standard is 1242 - reading 1949 ) thats after i install the cat. Today i change the oil, clean the throtle body, and fuel up the tank with 93 octane plus a lucas oil fuel injection cleaner and drove it for 15 minutes and fail, but this time it was worse. ( HC readings 240 and NOX readings 2968 ) can some explain if any idea please help me. The motor is a D16Z6, cold air intake, magnaflow cat, and everything else is stock. thanks

bluedragon

Well my friend had to put three cats on his hatch to get his to pass emissions is hell

canadaek

well hc are unburned fuel and nox is created from high cly temp so check your timing and oxygen sensor . is your converter a 3 way (hc/co/NOx) or just a 2 way (hc/co) . 93 octane actually burns slower so this will make your # worse . try something with some ethanol (10-15%) it's an oxidizer so it will aid in reducing hc

DCRB

have you done a tune up, and replaced the o2 sensor recently?

jesus jimenez

so by me adding 93octane instead of my usual 87 octane made my numbers worse? the few things that i have done is change the oil, spark plugs, new dizzy, fuel pump, and of course add 93 octane fuel plus an additive thinking it would pass since a co worker said it helps having higher octane. The new cat i'm not sure all i know is that is 49 state legal according to magnaflow

canadaek

ya the way high octane fuel reduces detonation is because it has a slower burn rate . and some 49 state legal cats only do hc/and co the only way to reduce it in a car without an egr valve is with timeing,fuel mixture and the converter. some times a decarbonizer also helps

Arthas

I cant believe what im reading. One question, how did you think you would pass with a test pipe? You NEED a catalytic converter to pass haha.

If you want to pass put an OEM or OE spec catalytic converter on there. Those high flow cats will not help you pass inspection, they are high flow for a reason and passing smog isnt one of them.

Stop being a silly putting 93 octane on a stock Civic, it doesnt make your car run any cleaner all youre doing is wasting money and making your car perform poorly. Run 87 like the manual calls for.

Arthas

Do you live in California?

jesus jimenez

Well thanks for the info, no I don't live in Cali I live in Texas so I go throught this web site to find as much info as I can. About the high octane well that's my fault for not getting informed well it happens and the cat I felt it was easier than going through the hassle of going oem since either they don't have it or is just way to expensive to buy believe me I work in the auto business. I took some advice and check the timing and it was way off so that's a start for now.

2LEM1

iTrader: (1)

Mine says Premium Fuel Only doe.

RatRod

put your stock air box back on, and if you don't have a stock muffler get one (I'm just assuming where as you didnt have a cat...)

Arthas

LOL I meant for the Dx guys ahaha.

sir_civic

use a cat frm the obd2 y7. thats wut i did on my 94 ex.

jbpnoman

My Civic is a DX, should I use low test?

Leetfade

Make sure you drive the car around for at least 20 minutes before going for the test as well.

When we had emissions in Ohio I had a POS car that kept failing. I put lower grade gas in, beat on it on the highway and it finally passed.... All seems counter-intuitive but it finally passed...

The rest has pretty much been covered.

canadaek

muffler has zero effect on emissions its for noise only !!!!

RatRod

so you must think back pressure is something you feel when you bend over? Computers compensate, not self tune. You get better fuel mileage with a real muffler. Sir civic said it though, OBD2 cat.

canadaek

ya i'm a certified emissions repair/inpector but i don't know anything about it . then why do free flowing exhausts make more power ? is flowmaster,magnaflow,borla,hks,greddy all wrong ?

pityocamptes

Does methanol help? I've always heard using 99% isopropyl alcohol works (oxidizes) but others say methanol will also drop the numbers...

kwong2001

It took me 8 tries to get the car to pass emissions. The first 3 were without a cat, the last 5 were with a brand new high flow cat. On the 8th try I was prepared to do the waiver my state offers. However, when they ran the test (which a guy from the Dept of Ecology was there for), it actually passed.

The HC's dropped from over 400 down to around 30 or so. The Dept of Ecology guy said it was because brand new cats have a coating on them that have to burn off before the cat starts actually working. By the time the 8th test came I had around 150-200 miles since the cat was installed. I also had the car revving to 2.5k rpm for about 15 minutes in the parking lot to keep the cat nice and warm which probably helped.

Interestingly, he said the cat probably won't last through the next 2 or 3 tests I have to do (before the car is emissions exempt) since the HC's are so high. I'll probably end up getting a test pipe fitted and pulling the cat so I can just use it for emissions purposes down the road.

RatRod

ya he is right, my magnaflow highflow cat didn't last a year it the half the metals all broke apart inside and were turning very whitish and brittle. Out of curiousity what did you have for a muffler, a can or stock? And are your pipe tests consist of just an idle period or is there revving involved?
and Canadabaek you think you know you giver pal. I'm not getting into it with somone who wants to argue emissions with performance exhausts and making power...

kwong2001

The car runs an apexi muffler, not sure the model. The test was done at 25mph and at idle. The idle was the part that I had trouble passing.

dE.fUsEd

1 bottle of rubbing alcohol.
O2 sensor.
AFPR would help tons.
Make sure the car is hot as hell.