I took my emissions test today and failed on HC and CO%.

My HC's were 190@15mph (limit is 124) and 174@25mph (limit is 120)
My CO% was .72@15mph (limit is .70) and .81@25mph (limit is .67)
Passed NO fine.

Is this close to passing or is it way off?
and are there any things i can do to make it pass? and tricks like boosting the octane of the gas alot?

 

What is your set up? What ECU you running?

Any codes? O2 sensor working properly?

Sounds like you are on the verge of passing, just probably running a little richer than the norm in order to pass emissions.

That is pretty close to passing, you just barely missed it.

If you have any codes, fix them, the ECU is most likely running in a mode that could cause you to run a little richer than in closed loop mode. Make sure the O2 sensor is good, as well as full working Catylatic Converter.

If you are also running a chipped ECU, try borrowing a stock ECU or another ECU that will lean the motor out a little more to reduce emissions.

It will not harm your motor, just don't abuse the hell out of it. Being at 15 MPH and 25 MPH and such won't do anything.

 

it's a d15b7 with a d16y8 head (and every bolt on including full msd ignition), no codes, stock ecu, i'm prity shure the cat and o2 sensor or good because my A/F ration gauge is workin good. but when i step on the gas hard it goes to fuel rich, should i lower my fuel pressure and retard my timing a little? and would boosting the octane alot help since higher octane fuel burns hotter?

 

Retard the timing a little, get yourself some octane booster, and set the fuel pressure to about 40 PSI at WOT.

 

ok, cool, thanks for the help

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bluedelsol &raquo;</TD></TR><TR><TD CLASS="quote">ok, cool, thanks for the help</TD></TR></TABLE>

np

 

how will retarding the timing do any good? That would make it run cooler, which would reduce NOx, but wouldnt help him pass emissions. If your fine on the NOx, just turn down your FPR so you run leaner. which would also increase your NOx a little, but your fine there anyway. How old is your cat is the most important question. If you have a new cat, then just turning down the Fuel pressure will be fine. If you have a cat that is older then 6 months old, you will see some really good improvments with a replacement.

Also, new plugs, fresh oil, a properly working ignition system will always help

 

aright well i took my re-test today and faild again, it got worse.

HC=201@15mph (limit 124) 229@25mph (limit 120)
CO=75@15mph (limit 70) 68@25mph (limit 67, this acually got better)
NO=157@15mph (limit 989) 333@25mph (limit 894) this got alot better but was fine before

i retarded my timing, re-set my ecu, added alot of octane booster and loweres the fuel pressure, WTF? why did it get worse?

 

How old is your cat?

 

i dont know, its been on there since i bought my car last year

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bluedelsol &raquo;</TD></TR><TR><TD CLASS="quote">aright well i took my re-test today and faild again, it got worse.

HC=201@15mph (limit 124) 229@25mph (limit 120)
CO=75@15mph (limit 70) 68@25mph (limit 67, this acually got better)
NO=157@15mph (limit 989) 333@25mph (limit 894) this got alot better but was fine before

i retarded my timing, re-set my ecu, added alot of octane booster and loweres the fuel pressure, WTF? why did it get worse?</TD></TR></TABLE>

The reason why your nox got alot better is because u retarded your timing. But I think that hurt your HC's.

What is ur fuel pressure set at, and how old is your cat

 

a new cat and ull pass

 

for some reason my FPR gauge isnt working so i dont know what is is set at, my cat has been on there since i bought my car last year, it's a 94 del sol so i dont know when it was replaced last.

 

I'll say get a new cat and you should no problems passing.

 

do i need a stock cat to pass or will a high flow one work?

 

a high flow will work fine
just make sure its hot on the dyno

 

ok, thanks for the help, i'll buy one tonight, i'v been meaning to buy one anyways

 

ull pass with a new cat, just watch
it'll be night and day difference, ur close anyway
just make sure u do some fun freeway driving and get it nice and hot

 

aright, i got a new cat and it still failed. but just on the HC ppm's.

15mph:
limit-124 reading-273

25mph:
limit-120 reading-179

new O2 sensor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bluedelsol &raquo;</TD></TR><TR><TD CLASS="quote">I took my emissions test today and failed on HC and CO%.

My HC's were 190@15mph (limit is 124) and 174@25mph (limit is 120)
My CO% was .72@15mph (limit is .70) and .81@25mph (limit is .67)
Passed NO fine.

Is this close to passing or is it way off?
and are there any things i can do to make it pass? and tricks like boosting the octane of the gas alot?</TD></TR></TABLE>

So your getting 190 parts per million of HC and 67 percent of CO - what is your co2 reading -
Well HC reading is an indicator of a misfire and CO reading is an indicator of Rich mixture - since your CO is lower than Your HC you may have lean misfire - However, poss you o2 reading that way I see if it is lean mis. But anyway, if it is a lean mis check your fuel filter - remove it pour out the fuel into a clean bowl to see if is dirty (clogged)?

 

needs cat!!!!

 

i already replaced my cat, read my last post.

 

sorry i should read more!

 

obd1, 94 del sol

 

check timing, coolant temp sensor may cause it. running to much fuel and not enough air. o2 sensor may cause it if it's running lazy. but do timing first.