Emission Failed
 

Hi guys, just curious if any of you can give me some advice about what to do with my car (94 coupe Si)...Twice this month it failed the emission test and the first result was that the NOx level was so high (limit is 550 and mine had 1330), and the second one both the CO and the NOx was high (CO limit is 72 and mine is 77, NOx limit is 550 and mine is 1040). After the failure from the first test my friend adjusted the dist cap coz he said it might help. My Cat converter is new and it was installed this April but it's universal. I also just put in a new midpipe ( from the cat to the muffler) bcoz the old pipe broke down due to rust. Except for the exhaust manifold, the whole exhaust system from cat to the muffler is welded and after market. Also, my car has JDM d15 in it. I have this car for almost 2yrs now and have never change anything to it, like dist cap, fuel filter, sparkplugs/wires, except for the airfilter which i did last summer.

The guy who did the test told me that the converter may have something to do with the failure, but it's brandnew though, it's universal however. Is it really the converter that is failing my car or do the D15Vtec has something to do with it? Please, all mechanic guys, let me know what action to do to get my ride pass the E-test. Thanks in advance to you all..

Usually a high NOx means your EGR valve is faulty, however I don't think your car has an EGR valve.

You should try putting in new spark plugs and maybe you should also check your PCV valve, and put a new one in too. Malfunctioning PCV valves will result in high NOx levels. Also, get an oil change just for the hell of it.

Try it, it might actually work.

Fresh oil and pcv valve will help etest. Also his civic does not have an egr valve.
Moreover did you heat up the cat before going? Take it for a highway drive for 10mins or so then when you pull into the etest place leave the engine running. Cat works better when its hot. Changing sparkplugs could help a bit if they are old. Also a new distributor cap if the contacts are worn badly.
Otherwise you can try the sure pass from ctire.
GL

This is more than a PCV valve and a oil change lol. Id start at a FULL tune up(plugs,wires,rotor,dist cap etc), Oil change, PCV, clean/inspect Air filter, CHECK your 02 sensor. Before the test run the car to empty pour a full tank of 91/94 oct fuel take her for a long highway run couple hour cruise then go for an etest. If your still scared pour 1 litre of methyl and 1 litre of 94 and run the etest lol If you fail after all that your into timing/faulty cat etc etc

what kind of cat do you put on? i dont mean direct bolt on or universal i mean the make of it.

Catco is know as a cheap universal converter, you can put on a new one and it will fail all day long.

magna flow makes a nice cat and pretty affordable aswell. also guaranteed quality product.

but yes oil change and plugs is a good start alone. but since your car seemed to fail that bad and in a few spots not just one, i'd say your cat is balls bud.

Hmm that's what I said the previous time he asked, should change the cat, but didn't want to sound like a broken record lol

Thanks to all your suggestion and comments guys...Well, I dont know what brand my cat is but it's installed from MIDAS when my cat/pipe was rusted and broke down..before i went for my second test i put hte highest grade from Shell (V-Power i think) and drove it for 15mins in the highway and still fail...I will do your suggestions maybe little bit at a time since im financially tight and see from there..Again, thanks guys...hope to hear more....

Additional curiosity, would the ECU got sumting to do with it as well since this is a JDM engine???

what's your HC reading like?

Sorry it's not the CO% that's high - here's the actual result:
HC - limit 72 mine 77
CO - limit .40 mine .26 pass
NO - limit 550 mine 1049

catalytic, o2 or timing or wrong ecu one or the other or a combo lol