My JDM integra Si-VTEC failed on CO emissions this morning. It was well under the limit on the low idle test, but on the high idle test (2570rpm) its was over. The limit is 0.3% Volume, my car read 0.32%vol, so it was just over a tad. I have a DC JDM 4-1 header which i think caused the problem as it was well under last year with the stock header. I have the timing set at +18degrees, would screwing it back to +15 bring me down sufficient to pass on the CO reading, or do i need to bolt on my stock header to get it down? Also i dont think the engine/cat/exhaust was up to full temperature before hand as i live beside the testing centre and slept in too late and couldnt take it out for a good long drive to get it well heated up before hand, although the tester told me he tried it 4 times to give the engine time to heat up sufficintly but just couldnt get it under. Any advice greatly appreciated!!!!!

 

i would retard the timing and take it for a long drive i would also sugest running a bottle of rxp through it. hope this helps

 

I went to a mechanic friend this evening, he suggested as you said, a bottle of injector cleaner, and retard the timing back to +15, also i'm using iridium plugs which he said burn at a high temp so he also suggested putting back in the stock NGKs and seeing how that goes. If that doesnt work, i have a Field SFC which i can hook up and lean out the mixture between 2000-3000rpm by 10% which should get me through, and if that fails (which i dont really think it will) i'll just have to bolt on the stock header and go with that along with 15+ timing and stock plugs, and if that fails, then i'm lost...........

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mugenracer &raquo;</TD></TR><TR><TD CLASS="quote">..... Also i dont think the engine/cat/exhaust was up to full temperature</TD></TR></TABLE>

Bingo..... you found your own problem.. If that cat is not lit off, you don't stand a chance on CO. Your so close, just heat that puppy up for a few miles and you should be fine.

 

I've been told i should stick back in the stock NGK plugs (i've in iridiums at the moment and they reckon the figure should drop a little with stock plugs)
The oil temp during the test was 97degrees (Celcius) so the engine was fully warmed...wouldnt the cat have been fully heated too? Bear in mind its a JDM cat and so higher flowing than USDM cats and so easier to heat.
Retard the timing a few degrees
Dump in a full bottle of injector cleaner
Anything else i could do????????

 

OK if the oil was that hot you were up to temp and the Cat would have been lit. I read it again where the operator did you a favor and ran it thru 3 or 4 times.

You were also on track about needing to lean it out a bit. If the cat is functional, and hot high CO comes from too much fuel or misfires and oil burning. Without any misfiring, I do not think changing plugs will make a difference. Injector cleaner never hurts.....

Your on the right track. You are close for the pass criteria, but a bit off for a good closed loop system. I just pulled some old emission certs on my trucks, all near 100 K miles, 0.02% CO, 0.06% CO 0.01 %CO, and my wifes beater Buick with 200 K miles was 0.10% CO, thats a 1987 with a lot of miles. So that will give you a little comparison.

May want to dither the oxygen sensor if you fail again.

 

Put in a few gallons of denatured alcohol and drive around for a while before so that your catalytic converter can heat up

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BigMoose &raquo;</TD></TR><TR><TD CLASS="quote">

and hot high CO comes from too much fuel or misfires and oil burning</TD></TR></TABLE>
CO is caused by to much fuel. (rich condition) But missfires and burning oil will cause high HC.

 

Your absolutely right Chiovnidca. I have to start thinking before I type! He only said his Co was out of bounds, not CO and THC.

I stand corrected.......... thanks for the clarification!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BigMoose &raquo;</TD></TR><TR><TD CLASS="quote">THC.
</TD></TR></TABLE>
LOL, what kind of fuel are you using?

 

A dirty crank case can cause a high CO reading . I have fix many emmission failure due to dirty crank case. I recommend a oil change on top of the plugs and putting the timing back to factory spec.

 

I'm using 95oct unleaded...its all we have over here. the oil was changed less than 300miles ago. What is the factory timing figure? i was going to screw it back to +15 from +18.

 

Update: Put the car in this morning, they took an initial reading and it was higher than on the test day (0.4% vol) anywho, i fitted new NGK stock plugs and screwed the timing back to +15deg, reset the ECU and took the car for a blast, stuck it back on the krypton tuner and holy **** the CO dropped to 0.27% (above 0.3%=fail) The car runs like **** at +15, it bogs like crazy and theres NO power below 5k rpm, but at least i'll get through emissions then i'll just screw it back up to +18 and screw the environment