Let's hear it for California. Anyway...

97 civic ex
d16y8
AEM cold air
DC header

Guy says its most likely the cat.



Any advice?

 

Looks like your cat and o2 is gone. Make sure you don't have any exhaust leak. Change the cat and o2 sensor and make sure car has no exhaust leak and you will pass. Make sure the timing is right.

 

Its saying you didnt pass the OBD self test I would check the computer and make sure its working correctly beforer i replaced a cat. atleast that in az that means there is a check engine light on or they couldnt talk with the computer. hope you pass

 

I agree. It could also mean that the ECU was recently reset, and the car has not yet been driven enough to make all systems ready.

 

I had another D put it cuz the previous one was knocking and burning oil. Only driving weve really done it it was a mile here and a mile there so i could get in some stick shift practice. I'll drive it around some more then go back later in the week and do another pre test.

 

1. Find out why your engine light is on.

2. There are tests that the ECU does to check the o2 sensors/heater, cat, & EGR system. If there are more then 2 tests that have not passed/completed, you will not pass the OBD check. Usually it takes about 35-100 miles of driving to complete the readiness tests.

3. Warm up your cat. Drive around on the street alot. I was lucky at the test only place I went to. The dude let me rev the car to 4500rpm for ten minutes to warm up the cat before he tested it.

High NO% and HC% usually means Cat and/or o2 Sensor. You will notice that your getting horrible gas mileage if your o2 sensor is not working properly. O2 sensors are cheaper then California cats so get a new o2 sensor on Amazon, or oxygensensors.com first. Then retest

 

We drove around for a good 30 minutes on and off the freeway and never saw the engine light come on. So im guessing as someone mentioned the ecu isn't reset yet. The gas mileage isn't looking too out of the ordinary, is there a way to test the 02 before committing to a replacement?

 

the egr valve helps with nox so i would clean
the carbon off that make sure its clean

to check the o2 sensors get a test pipe then use a
realtime scan tool to make sure the two o2 sensors
respond the same this can tell you if an o2 sensor is bad


i found this it says honda drive cycle dont know if it really is

http://wiki.answers.com/Q/How_do_you..._a_honda_civic

hope it helps

 

Just to let you know, the D16Y8 engine lacks an EGR system.

 

sorry didnt know that, he said he put another d in it so idk sorry

 

I JUST BOUGHT A 96 GSR, ITS THE SAME THING..FAIL AT 15MPH AND PASS @25...WEIRD..SO ITS THE CAT TOO?? I HAVE A BUDDY WITH AN 00 CIVIC SI HE FAIL @15MPH AND THEN WENT TO ANOTHER SMOG SHOP PASSED IT..REASON"" HIS UNCLE SAID CAR WASNT WARM/HOT ENOUGH..? SO HE PASSED ON THE 2ND SMOG SHOP..

 

You had a check engine light and tried to get your car smogged? lol... I'd try to find out what that code is first.. Awful lot of HC even if you had a failed cat.. Sounds like you could have misfiring or some condition where you don't have proper combustion leading to lots of HC, CO AND NOX...

If he has a rusted out exhaust manifold, he needs to get rid of the rust in key areas and or run a ground wire with an eye hole to the O2 sensor. The o2 sensor uses the exhaust manifold as a ground and if the part where the o2 sensor screws in is rusted and or the bolts that go into the block are also rusted, he'll have a weak ground and therefore the o2 sensor won't work.

 

"pre-heating" a catalytic converter is an old trick to pass a car that wouldn't ordinarily pass. if your car can't pass without resorting to trickery like this, then it shouldn't be passing in the first place. Another thing smog techs like to do is suggest a new catalytic converter because a new one always works better than the old one but unfortunately this doesn't deal with the underlying issues as to why the car is failing smog in the first place which means you'll have a bad cat in a few years.

 

You're running extremely lean. When there is combustion, the engine runs hot and NOx emissions form. When there isn't, the engine misfires and raises HC emissions.

As everybody has already mentioned, pull the MIL code first.

 

My God,

Some of these answers are ????

First of all, he failed the check engine part for monitors. Not codes! You need to drive around with a mix of freeway driving and city.

His O2 is way up suggesting exhaust leaks. Fix those first!

Also driving abit is needed to clean out the cat after it has been sitting for a while.

Then try the test again.

 

5 month-old thread -- I presume that the OP has moved on.