My son purchased an 89 Civic. He took it to get emissions tested today. It failed the HC PPM Idle with a 418 reading/220 limit (from what I have been reading thats pretty high). The Cat passed as well as everything else. I am a shade tree mechanic and would like some advice on what I need to do to make this pass the test. Let me know what other information you need and I will do my best to answer. Any help would be greatly appreciated.

 

Even though most of the engines in 89-00 Civics are similar, I would repost this in the CRX/EF Civic forum right under this one on the main page. That forum is for Civics and CRXs from 88-91.

 

HC = essentially unburnt fuel

If you are a shade tree mechanic then you should know the basics. Pull the plugs and check them out - inspect the cap and rotor - when was the last time the oil was changed - does it burn oil - did you get it fully warmed at highway speeds before you tested... Plenty of stuff to get you started.

 

Replace the O2 sensor and change the oil. Reset the ECU and get it re-tested. A rich mixture = high HC

btw, welcome noob. This is a good 1st post.

 

Appreciate the replys. Oil was recently changed...within the last month. I'm going to replace the plugs and wires as well as the O2. Will let you know what happens. Thanks again.

 

I recently failed with an idle HC reading of 380 ppm (220 is the standard here).

What did you do and did you ever pass emissions?

Thanks.

(BTW, D16A6 engine in a '89 CRX Si)

 

What octane fuel did you run?

You want to run the LOWEST octane you can without detonating.
This helps for a more complete burn of fuel.

Make sure you have a strong ignition.
At the least change out the spark plugs.
Verify your that that the distributor cap and rotor are in great shape.
Have the plug wires tested or replace with quality wires.
Make 100% sure your timing is set correctly.

O2 sensor (even if just lazy and not completely dead) would fail worse IMO, but if you are up to spending the money then maybe change it.

 

sorry to thread jack but that sucks that your state has a emissions law (that are enforced)

 

I was running 87 octane.

Based on reading here, I plan on:

1. new spark plugs and test the spark plug wires
2. new distributor cap & rotor
3. check the timing
4. change the oil to 10W-30
5. new air filter (possibly run no air filter during the test)
6. keep the catalytic converter as hot as possible before testing

If I still fail, possibly a new oxygen sensor & possibly a new cat... Or clean the injectors?

 

I know. I just moved from Pennsylvania (no emissions check unless near philly or pittsburgh - I think) to NJ.

 

Changed plugs and wires...all it took and we passed with no problems. Glad it was that easy.