hi, I did a tune up on my daily driver I recently bought (162k miles) 95 Honda Civic EX. The spark plugs are motorcraft from Autozone btw.
It passes the High Speed Tests (HC, CO, CO2) but it fails the idle test for HC (hydro-carbon).

The car does tend to idle a lil rough but not bad for a 162k mile car. But maybe that "lil rough" idle might need some work.

The 1st time I tested the car, it was running 88 octane (or I think 87.. it was the middle one in between 85 and 91). I also had a CAI on it and everything else was tuned up except for the spark plug wires.
It got 509 out of 220ppm (FAIL) on the idle test

Second test: I decided to go back at using the stock air box and bought a new filter along some spark plug wires that I had from a previous Honda 88 CRX HF that were barely used.
And guess what? It failed worse. This time it got 595 out of 220ppm on HC. This was after putting the stock air intake and refilling 6/7 of the tank with 91 octane

What can be causing the HC to get worse?
EGR? O2 sensor? CAT?

The dude who does my tests says I should use some sort of "injector cleaner" because it cleans through my engine. He also recommends using "Guaranteed to Pass".
Anyone have any exprience with similar products? Do they work?
I have heard that "Guaranteed to Pass" is crap aswell as "injector cleaner".
I hear seafoam helps a bit tho.

I really need help passing my car, i live in Utah and there isnt anyone at all that takes bribes because the state has been cracking down. The Wasatch Front is heavily poluted...
Any help would be GREATLY APPRECIATED. Need the car for school this summer.

 

changed oil lately?

also, motorcraft are among the worst plugs out there... get some ngk's.

change oil, change plugs, run a bottle of Techron fuel injector cleaner through it (complete tank of gas), refill with 91 and go get checked and see if you pass.

 

Forgot to mention the oil change. I went with high mileage synthetic mobile 10W-30.
hmm, never knew that about motorcraft.

Stupid question, but the North American 95 Honda Civic EXs in 1995 came in ONLY a 1.6L Vtec engine right?
Im sure its right but at autozone or where someone needs my info, they always ask if its 1.5L or 1.6L. Im always wondering why they ask because shouldnt it be on there systems that they came in ONLY a 1.6L

 

I failed bad with the same car as you just recently. I was over 500 ppm HC at idle as well and when I passed it was down to something like 40ppm.

Heres all I did, new ngk plugs, new ngk wires, new oem cap and rotor, thats it and it went right through. High hc is indicitive of unburned fuel, take a look at your cap and rotor and make sure your ignition timing is set correctly.

 

yes the ex's only came with the d16z6 but along the civic line that year there were 4 different engines, make sure you have the correct heat range plugs, my car had the wrong ones too so they may have been an issue with my car as well.

 

do they look under the hood for inspection? i failed idle test... i pulled a vacuum tube on my intake manifold and it shot way below the acceptable limit.... cant comment on which one it was because my mechanic did it for me but im sure someone else has gotten through on this method....

 

Guaranteed to be a waste of money is what they should call it... like somebody else said hc unburned fuel the higher the octain rating the slower the fuel burns so 91 is not a good idea. some ethanol would help as its a oxidizer. i would look at you o2 sensor, (you can test it with a good dvom ) ignition timming clean the throttle body and idle air control valve most common is the o2 sensor also what where your other readings? NOx ,CO,HC on drive cycle and CO,HC at idle ?

 

also it helps to drive very "spirited" before arriving to ensure the cat is heated up enough. Check your ignition timing as well. You don't have an EGR. You can test your cat by measuring the inlet and outlet temp, the outlet temp should be roughly 100F higher than the inlet.

 

TEST 1: Used spark plug wires with unkown mileage, Motorcraft brand spark plugs, 10W-30 synthetic high mileage oil change with filter, CAI
High Speed Test
HC (ppm)
171/220 (pass)

CO%
.67/1.20 (pass)

CO2 %
14.0 @ 2526RPMs

Idle Test:
HC (ppm)
509/220 (fail)

CO%
.71/.120 (pass)

CO2 %
13.0 @ 779RPMs

TEST 2: after putting on my barely ever used 88 Honda CRX HF duralast spark plug wires from like 2 years ago that were laying around. Also, after putting the stock air intake with a new filter.
High Speed Test
HC (ppm)
182/220 (pass)

CO%
.62/1.20 (pass)

CO2 %
13.5 @ 2530RPMs

Idle Test:
HC (ppm)
595/220 (fail)

CO%
.71/.120 (pass)

CO2 %
12.6 @ 739RPMs


Tomorrow I will try NGK plugs, NGK wires, new cap and rotor, seafoam, fuel injector cleaner and if necessary, new O2 sensor.
The distributor is brand new. Last owner had to replace it. The cap looks new, I am going to check the rotor tomorrow.
Im thinking that the choice of going with my old plug wires was a bad choice. Ill keep this thread updated on what happens with NGK plugs and NGK wires.

EDIT: I dont think Utah checks for NOx. But I might be wrong

 

They do look under the hood. But they dont care what they see under the hood. Utah doesnt have any "California laws" or any of that bullcrap. I can run a V8 and they could not fail me for it.

Interesting... anyone know of said trick?

 

Any name brand O2 sensors to stay away from?
I been searching around a bit for a guide for "how to check ignition timing". Anyone have a link to one?
Also, sense I am going with NGK spark plugs, which exact NGKs should I get? The most expensive NGK plugs? Does it matter which NGK plugs I get?

 

as long as there the right # the cheap ngks work just as well as the expensive ones they just don't last as long. to set ignition timing warm car up fully turn off all accesorys jump 2 pin connector under the dash on passgerside just above the kick panel then use a timming light hooked to #1 plug wire you want the middle mark of the 3 on the crank pully (16* btdc) not the one mark all alone. egr only reduces NOx so if they don't test for it don't worry about it . normally if NOx goes up (its caused by high cly temperature) HC and CO go down . so if you advance your timming as much as you can with out causeing detonation it will reduce your HC and CO levels but your other #'s are on the high side even though they pass could be a sign your cat is on its way out.. i used to be a test and repair tech here in canada the most common causes of honda's failing where O2 sensors and Cats and one tps sensor( friends B16 ef civic)

 

Any opinions on Bosch O2 sensors?
They were the only ones Napa and AutoZone had

 

bosch are ok lots of companys use them (toyota subaru )

 

ill take a picture of the hose and where to unplug it tommorow i had ridiculously high failing numbers and once i pulled it...it went real low and i passed

im sure you could do it but i wouldnt reccomend driving on it other than in the dmv/mva parking lot im guessing its running real lean

 

Another question:
So I changed the spark plugs yesterday along with the wires for some NGKs. I noticed that on the motorcraft spark plugs I had on there, they had "black soft carbon". According to the hayness car manual, that can be caused by bad ignition (spark, rotor, cap, ignition timing).
This basically rules out a bad CAT (i hope)

Anyway, I was on CRXCommunity.com and some guys there had the same problem as me on passing emissions (idle, HC) and what they did was turn the distributor 1/4" towards the front of the car and they passed.
So I am going to try that aswell as some 44K. I have heard many good reviews of this product. Around where I live, many emissions stations recommend this product to people who dont pass.


I am going to do another oil change and this time go for non-synthetic high mileage. Im just going to keep the old synthetic oil for my MX3 or something. I think my car is starting to leak a little oil for the first time. Synthetic for high mileage SUCKS!

 

Back from the dead... whatever happened with this? Friend is having same issue, told him to advance the timing with the distributor but not sure if he tried it.

 

yes id like to hear what worked and what not

 

So basically, I need to replace the cap and rotor and twist the distributor?

 

you might want to loosen the bolts first

 

well, yeah. lol
Oh, and I will keep you informed. Gotta give credit where it's due, you know?

Another thing I was wondering, would twisting the dist. cap stop sputtering? Ive noticed sometimes when Im in 2nd gear, the car doesnt go like it should and its sputters til I shift gears.

 

Hey sorry guys for not responding.
I ended up passing last year because my timing was off a bit. I barely passed.

Emission testing again this month. Took the Civic to get tested and it failed. I only added about 7k miles to it sense.

My timing seems right, new NGK plugs and everything else is still good.

I am going to to try re-adjusting the timing yet again...
If this doesnt work I am thinking of a new cat

I dont want to give credit where its not really due...

But last year, I put on some 44k from Napa (or is it called 66k?). You put it in the gas tank mixed with gas, run it with 91 than when you get to a 1/4 left of gas, you put in new gas (87) and its suppose to pass.
Keep in mind, this is after re-adjusting the timing but before the test where I passed.

After you re-adjust the timing, your car should feel smoother at idle and my car felt much smoother.

This year I failed the HC idle test by just about the same number as last year. However, I also failed the high speed test or whatever its called by a small 20ppm on the HC test.

ALWAYS READ THROUGH THE CAR MANUAL BEFORE DOING SMALL THINGS LIKE TUNE UPs
Reason why i say this is because I was able to pin-point my problem to timing because the manual mentions that too much carbon build up on plugs indicates bad timing and HCs. BUT... then again, could it have been the 44k fuel additive I added that helped me pass?
hmm...

 

Just wanted to provide an update

I took the Civic to Midas and they have a service where they find why a car wont pass emissions for $90.
Problem: Ignition timing

I couldnt believe it, I swear I thought I had it right. Maybe the timing gun is off.
Anyway, the new results came in and the HC numbers are MUCH better.
Car passed

 

You know this post is so old that no one has answered anything for over a year? Why did you reply to this?

 

Lol