I just recently picked up a completely stock 88 civic STD (4 speed stick) hatch, and I am trying to pass inspection. But it won't pass emissions!

First time I took it (completely stock, no tune-up) I got 340ppm HC (hydrocarbons) at idle, and 329ppm at 2500RPM. Limit is 220. For CO, I got 8.79% at idle and 10.32% at 2500RPM. Limit is 1.20%. CO% + CO2% at idle was 18.28%, 2500rpm was 18.96%. They don't fail us for that one.

After investigating, I found out the car has a test pipe on it. I put a cat on (OBX high flow that I had laying around), and did a partial tune up (plugs, dist. cap and rotor, oil change, coolant). Took it back and had these results:
HC 392ppm (idle), 475ppm (2500RPM) Limit 220ppm
CO% 8.61% (idle), 10.74% (2500RPM) Limit 1.20%
CO% + CO2% 17.36% (idle) 18.33% (2500RPM) No limit

So, I decided to "finish" the tune-up. I did plug wires, O2 sensor, air filter, fuel filter, and cleaned out the throttle body (because pedal was sticking - not emissions related). Car did seem to run better (used to hesitate somewhat, now I don't notice it). Did even WORSE this time!

HC 510ppm (idle) 583ppm (2500RPM) limit 220ppm
CO% 9.26% (idle) 11.16 (2500RPM) limit 1.20%
CO%+CO2% 18.05% (idle) 18.81% (2500RPM) no limit

I'm stumped as to what it could be. We think it might be that someone plugged an emissions-related component, and today I am going to check that out. Also I was thinking that the cat may be **** (its brand new, but maybe it's too "high-flow" and not enough "cat" if that makes sense - it does have the honeycomb in it though). But would the cat make it worse? I just don't understand why I am failing so bad. It is the D15 stock engine with 133,000 miles on it. No modifications at all! It runs great though...As a last resort, what is a good type of alcohol to run though it just to pass? Thanks!

-Josh

 

obx high flow cats still are not cats. get a real cat.

 

Hydrocarbons that high, sounds like youre burning oil. Is it smoking at all? I would think that bad, youd see smoke... Try getting some high mileage oil (I like castrol GTX) and some bardohl No Smoke.

Other than that, maybe youre not burning clean. Is there any fuel in your exhaust? That would also cause high hydrocarbons. Run some injector cleaner through it, and make sure one of the injectors isnt stuck open.

Also im hoping youre getting the emissions test done when the car is warmed up... if the car is cold your numbers are going to be way higher. Try and drive a few miles on the highway before you take it in, and keep the revs around 3k while youre waiting.

 

Thanks for the replies!

Surprisingly, I'm not burning anything. No smoke at all! Sometimes I smell a little gas, which makes me think it runs rich. But 3 weeks ago I changed the oil and coolant, and the levels for both have been perfect. I drove over 1000 miles in this time and the levels haven't fluctuated.

The inspection station is actually right off of a highway, so the car is nice and warm when I arrive (plus it's been like 85-90 degrees here everyday so it warms up fast). And I did keep the RPMs up while waiting.

I'll be sure to run some injector cleaner through it, but how can I tell if the injectors are stuck open? If I listen to them? Isn't there a method of putting the tip of the screwdriver on each one and "feeling" it open and close (maybe that method doesn't work anymore :D)

Also I am going to go through the vacuum hoses, they all seem to be cracking and brittle. I'll let you know what I find! Thanks!

BTW - I drive like a grandma most of the time, and I only get like 28-30MPG (mostly highway) in this little hatch - shouldn't I be seeing around 40MPG+?

 

Ok now its idling like complete **** - maybe this is a step in the right direction - if I fix the idiling problem my emissions issue could be resolved as well. Let me fix the idling thing (its a vacuum leak) and I'll report back if that was it :D

 

Ok, its been a week but I've done a few things...and I got it tested again (failed of course!). Fixed the idling issue (vacuum leak), and adjusted the idle to 750RPM. Idles perfect now! But, sometimes I throw a code 7 (TPS).

So I retarded the timing a little bit (turned the distributor clockwise, I have a timing gun but I can't find the timing marks on my crank). I ran a bottle of STP fuel injection cleaner last week (with a half-full tank), then filled back up halfway again. Then today, I ran the tank down to right at the E line (my gauge will go a little under that before the car runs out of gas...so I was almost out), and I added 4 bottles of HEET, and 2 quarts of SL-X denatured alcohol (I had 87 octane gas in the tank). Took it to the emissions station, and for Hydrocarbons I got 398ppm (idle) and 254ppm (2500RPM), limit 220ppm. CO I got 7.87% (idle) and 8.95% (2500RPM) limit is 1.20%. CO+CO2 at idle was 17.83% and at 2500RPM was 18.35%.

So compared to my last tests, these are the best results yet. HC is almost there...but why is CO so high? Keep in mind I am not smoking at all, and I'm not loosing coolant or oil. Gas mileage is around 32MPG.

I have a couple questions though. I bought a Hayne's book (yes...I know...but their emissions equipment section is actually interesting!) and it says that my car (the 1.5L DPFI) isn't equipped with a PCV valve, nor an EGR valve. Good, because I can't find either on my car. Is it supposed to have either of these? Anything else that could make my CO emissions that high? I think if I can get the CO emissions down, the HC will come down just enough to make it pass...

 

Another thought...I have this generic high flow cat on there (before I put it on I looked and it does have the honeycomb thing so it isn't just a straight test pipe) but I am 2 seconds away from going down to the local muffler shop and paying somebody $100 to throw a regular cat on there...would the cat lower my CO emissions that much?

I want to fix this within the week (my temp tag runs out on saturday and then I'll have to switch the insurance back to my integra and hear my insurance company bitch ) Any body have stories about if switching from a high-flow cat to a regular one decreased their CO output by a lot? Thanks!

 

High flow cats just barely make it through the emissions tests brand new, so it could be your problem.

CO has to do with poor combustion. So a weak spark, vacuum leak, leaky injector, bad compression, valve adjustment, lean or rich misfires, and timing are all important.

Get your timing set before anything. It makes a big difference when CO is up, unless you have other problems.

A 88 civic with a 1.5 does have an EGR valve I believe. And your CO could be because of the EGR valve. Do a search on EGR for more info to see if you have one and for the test you need to perform.

Timing and Cat is where I would start first.

 

Ok, I put a new cat on it (a normal one) and went back and got it tested. Failed again, and the CO went a little higher, HC was lower (sorry left the paper in the car). It might have gotten worse because there was no more additives in my tank (just 91 octane gas).

I am going to try to clean off my crank pulley and find those marks so I can set the timing like you said, and I'll look into the EGR valve thing. Also, the Helms service manual says I do have a PCV valve, so I will search for that. Thanks for all of your help I really appreciate it!

 

One thing...Run 87 octane when HC's are up.

You definately should have an PCV valve. Just keep looking.

 

Ok, I might be getting somewhere. I am throwing code 7 (TPS). Sometimes the light will go on while driving, but if I flick the key on and off it goes out. This may explain why it bogs when I first push the gas (like it hesitates for a second then responds to the pedal, if that makes sense). Seems to me like the ECU doesn't "know" how much gas to dump? I am going to test, adjust, and/or replace this sensor (if needed). Could this somehow make my CO reading off the wall?

Also, the PCV valve issue has been solved. It is right on top of the intake manifold, in the center. It's threaded in, I've never seen one like that. Anyway, I took the hose off of it, and put my finger over top, and it didn't make a noise, so I took it out, and shook it forcefully until it made that rattling sound on its own. Then I put it back in, and started the engine (with the hose still disconnected) and it does now make the noise when I put my finger on top. Maybe it's working now?

BTW, the test from earlier (brand new regular cat) was: HC 342ppm (idle), 242ppm (2500RPM) limit 220ppm, and CO was 7.32% (idle) 11.02% (2500RPM), limit 1.20%.

My plan now is to go through the Helm's shop manual troubleshooting flowcharts about failing emissions tests. Tomorrow when I get to work I am going to pull out the multimeter and test/adjust the TPS, and I also want to look at the EACV (Electronic Air Control Valve), that needs to be tested for resistance. I just hope that I find something out of whack that can be replaced, because I am running out of options (and time)!

But thanks for all your help!

 

Your ECU uses three main things to figure out your A/F ratios

MAP
TPS
O2 Sensor

so it could make a difference.

My bet is timing.

 

Ok, I reset my ECU and drove the car, and threw a code 5 (MAP sensor). Turned the key on and off, drove some more and then threw a code 1 (O2 Sensor). Not throwing a TPS code anymore tho?? I haven't reset the ECU for a while, and a week ago my friend was plugging in and unplugging **** (when we fixed the idle problem) but I didn't reset the ECU. It's idling ok though. Maybe the TPS code was from when he unplugged it? My O2 sensor is brand new and the wire is fine. Im going to try troubleshooting the MAP first, I didn't mess with the TPS yet. And as for timing, I can't find the damn markings on the crank! I'm gonna try cleaning it really good and look again, it sucks not having time tho! Thanks!

 

If you can't find the marks, here is what you can do.

Remove the #1 spark plug. Get a piece of wire, like a coat hanger and straighten it out. Put one end in the spark plug hole. When you turn over the engine, the wire will go up and down with the piston. When it's the furthest out of the hole, the engine is at TDC. Mark that. Then the timing mark is about 1 1/2 inches towards the front of the engine, from TDC. You should then be able to see the timing mark and get the timing set.

 

Ok, I did a lot today :D First, I reset the ECU (pulled hazard fuse). Then, I confirmed that the cam pulley was timed correctly with the crank, and it was. Then I set the ignition timing to 16 degrees. But the idle was surging from 700-1200!

So, I unhooked the EACV (electronic air control valve) and it stopped surging and stayed around 650-700. But the CEL came on (#14 EACV). That's the only one on now (I'm pretty sure - I probably should go check if the MAP or O2 sensor codes are on). I took it off and cleaned it with brake cleaner and put it back on and it's still surging, so I unplugged it again. That's where I am now. I can get a new one from hondaautomotive parts for $167...Should I just get that? Could anything else be causing the issue? I guess I don't have a vacuum leak because when I unplug the EACV the idle issue goes away.

But my gas mileage is horrible. I drove 167 miles and my tank is on E. It smells like gas!

So my next step is to get a new valve...right? Does this valve have any effect on emissions (lean/rich) or is it just an idle thing? Thanks!

-Josh

 

Any ideas? I might swap the IACV off my B16A integra, they look similar...I hope this works, but does it affect emmissions?