My 96 Accord 4cyl failed the CA low speed smog (hi HC% & CO&) but passed the high speed test. Also got dinged for aftermarket cold air intake (fixed put oem back on). Any hints on how to remedy the low speed emission issue

 

Could either be an o2 sensor not properly registering, or actually kinda sounds like your cat is going bad. At higher rpms the cat gets hotter working more efficiently. When i used to smog my vehicles i would always "super heat" the cat before it went in.


Posted from Honda-tech.com App for Android

 

"super heat" how do you do this ????

 

Rev the engine at about 5k rpms for roughly 60 seconds


Posted from Honda-tech.com App for Android

 

It's a five gas test, post up all the numbers of both 15MPH & 25MPH results.

 

15 mph fail
%co2 meas 15.1
%02 .01
hc ppm 54 max 88 meas
co% .50 max .69 meas
no ppm 430 max 490 meas

25mph pass
%co2 meas 15.1
%o2 0.0 meas
hc ppm 37 max 37 meas
co% .47 max .17 meas
no ppm 717 max 331 meas

note car was driven 5 mi to test station & sat for approx 25 min before test

 

She's running rich, find out why and fix the issue.

 

To narrow it down a little,
What are the possible causes for a rich condition???

 

Bad up stream o2 sensor, timing off at dizzy, stuck injector (dirty and not closing all the way)


Posted from Honda-tech.com App for Android

 

I'm sorry. That's backwards. The fuel injector part. I have been doing mechanical work for 14 ******* years now. And i still get rich/lean mixed up.


Posted from Honda-tech.com App for Android

 

check the condition of the rotor. cap. wires. and spark plugs. might not be getting enough spark to burn all the fuel at low rpm. replace spark plugs with ngk's if you haven't done it in a while

 

The results are inChanged the oil
Put in some hi ocatane gas
Put in a bottle of "Guranteed to Pass"
drove approx 125mi
got it hot
PASSED!Life is good today
Thanx for the tips

 

What were the numbers?
*you can't leave us hanging with a simple 'it passed'*