My car wont Pass emissions ... Ive been in three times and everytime ive failed the idle part of the test....

I got a 90 4door civic with a DOHC ZC motor... its running the PG7 ecu and ive changed out the Spark plugs, Wires, Cap & Rotors, And O2 sensor ... the car idles fine and seems to be in working order

So what other emission stuff can I check ????

Idle I got

HC: 456 to 220
CO(%) 4.82 to 1.2

the numbers are way out there ... And if you guys hav any tricks let me know to

 

my car failed too, its an 89 CRX DX with a ZC. I don't know what any of those numbers mean, but I was told I'm running to rich. I was also told that I should be using the map sensor from an Si(I think it was the map sensor). that my DX one is making run to rich. I haven't done it yet, but maybe thats our problem to. what kind of civic do you have? LX, EX, DX?

 

um.........if you've changed all that stuff and the engine runs good, you need a new catalytic converter. 5 bucks says i'm right.

 

Those are the kinda numbers I had when running the motor. What happens is when the fuel is running rich it doesn't quite burn completely so your left with a bunch of black smoke coming out the exhaust. You can probably tell if you can small that mmm mmm gas smell coming from your car. Just what red posted, yep you might need to change your plugged up catalytic Converter (Carsound, Random Technology, Catco....) That's what I did and I passed Smog with flying colors with my new ricey sounding Carsoun Cat Converter. Good luck

 

good thing i can pass inspection with any jdm motor having an inpection sticker hookup is key!

 

I passed emissions with my DOHC ZC on Tuesday on my 2nd try going there. Here is what you need to do...

-Run a lean ECU, PM6 or an HF ECU I hear will work also.
-Change your oil before you go to emissions.
-Get new spark plugs, make sure your air filter is clean, get a new O2 sensor also, they are like $40 for bosch ones. This way you know everything is in working order.
-Check ignition timing and set it to 16*BTDC.
-Run the lowest octane gas you can get, this way you know the fuel you are using will burn more completely (low octane burns faster, higher octane slower, if the ignition isn't advanced enough it won't fully burn high octane gas which will skyrocket your Hydrocarbon and Carbonmonoxide readings.)

If you do all those things supposing the engine is in good working order you should pass. I think I'm going to make a How-To on my website about this.

Also to someone saying you need a different MAP sensor that is not true. DX and Sis have the same exact map sensor, feel free to check the part# on the map sensors, they are the same. All a map sensor does is know if there is a lot of vacuum the engine is at lower rpms and if there is no vacuum than the engine is in high rpms. Its more linear than that but all it does is help figure out load, the ECU is which will decide how much gas to use by using O2 sensor input.

 

Thanks for the Response ... I was also leaning towards my cat but I didnt wanna think about it since the price for a Cat was $160 =\ and I already spent close to 150 on the O2 sensor and spark plugs ...(And Im using money I dont have)

But My friend has a ITR cat but i wasnt sure if a Highflow cat would would help it =\ I guess it wouldnt hurt to try it ......

and yea those are Brand spankin new spark plugs, wire, cap&rotor, and O2 sensor

I like the idea about the Lower Octane but ... its gonna take me about a week before I can burn off this high octane (I filled up half way on my gas tank) and I need to pass emissions by tommorro since i need to get tabs and transfere the title

But yea Ill give this a try tomorrow, and if it does pass please do make a How-to for this.

Oh yea mines a LX i beleive... not to sure .. it doesnt hav any power options and no tach ... just power seatbelts haha

 

Done...

http://www.fourthgenhatch.com/emissions.html

 

HF ECU will give you check engine light with code 12 - EGR Lift Valve - won't pass with Check Engine Light

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redzcstandardhatch &raquo;</TD></TR><TR><TD CLASS="quote">um.........if you've changed all that stuff and the engine runs good, you need a new catalytic converter. 5 bucks says i'm right. </TD></TR></TABLE>
Give him his 5 bucks. You cat is clogged / messed up.

Dave

 

Like I said earlier .. I came down to the conclusion that maybe the cat was screwed but 150 for a cat isnt really in my budget right now =\
thats why i didnt wanna put it into consideration ... but hopefully running the Si ECU, Low Octane and Changed oil will help me pass if not then siet maybe i might hav to sell a leg or an arm to get the cat =\ haha but yea thanks alot for the information guys