just went to the emissions test here in MD and i failed badly in Hydrocarbons.

i drive an 88 CRX Si w/ a B17 in it. Neuspeed 4-2-1 header and stock Si exhaust. Just replaced my O2 sensor about a week ago. running stock ECU and intake.

State Standard = 220 PPM hydrocarbons
my car = 544 PPM!!

the car should've been pretty warm.

i passed the other emission readings, just failed in HC.

my CO% = 0.91%, standard = 1.20%
my CO2% = 13.58%, standard = 6.00% (i guess it's good to be over??)

anyways, what's my problem guys? what should i fix? i was told it passed at idle, but not at the 2500 rpm test.

 

HC is fuel that went through the engine without being burned.
CO is created when gasoline is not completely burned. High CO (running rich).

When you have high HCs then your COs are usually up as well - it's no suprise to see that your COs are high.

Check your ignition system.
Make sure you don't have the timing advanced.

Check your air filter.

Are you getting any check engine lights?
What octane fuel? If you are running high octane, switch to the LOWEST octane you can run without having detonation problems. That way the fuel has more chance of completely burning off when it burns.

If you are ok on all those, go have your catalytic converter checked at an exhaust shop.

 

hey thx. yeah, i run 93 octane normally, so maybe i'll step it down to 91.

i was getting a check engine because of my O2 sensor the last few months, but i replaced it last week and it seems fine now. no more check engine light.

the engine runs great and i get good gas mileage, about 28-31 mpg usually. so that's why i'm surprised i failed my emissions so bad.

 

isnt 93 octane way to high to run on a b17...i thought they should only run on 87-89 because otherwise it runs really rich...i am not sure..anyone else know about this?

 

you guys have 93 octane at the pump? wow we only have91 and lower at the pump

 

hey man, i had a cheve last year that didnt pass because HCs because the egr hose was dirty, and the spark plugs were bad... I just passed my yellow 88 rex, but i kinda cheated- i used this anti-freeze stuff for ur fuel lines- the guys at Advance told me that I'd be burning pur alchohol with it in my tank... Where are u in Crownsville? I live there near the Wawa...
~Tim

 

the stick **** don't have EGR like the b16 b17 etc..

try some cleaner check timing check spark plugs replace rotor

get the cat check out like the pimp said. from the scores looks like with little work you will pass maybe do a pretest before you go in see if gets any lower. normal cat is around 14-15

 

Yea, and like someone else said, u dont need to run 93 in a stock B17. It has a firly low compression ratio. I started to run 89 octane for a while now and i actually gained 2 mpg, which takes me to 32 average mpg. When u say stock ECU, do u mean the stock P61 ?

 

Probably your Cat is bad. Since your O2 was bad enough to throw a check engine light, it would have caused the car to run rich for quite a while. This would damage the Cat.

 

yes, i run the P61 ecu.

i'm thinking it is my cat, cause it seems quite old and could be the original. u really think the bad O2 could have hurt my cat? the car ran fine with the bad O2 in.

i forgot that we don't have any 91 octane here, it's only 87/89/93. i guess i'll try and use the 89. i believe under B17 specs it says to use 92, but i'm sure 89 can't hurt any.

to fishin9975, i live close to the Wawa also. i live down in Arden.