lelopez

I've got a 1990 hb with a d16z6 swap including obd1 rewire, everything is stock except for a header. I went to test my car for emissions today and failed the low idle test, however the high rpm test passed without problem. I've used the search feature and have read some of the alternatives to help me pass, however I was wondering if someone had my exact problem and what was done to pass emissions.

These were my readings:
at 742 rpm
Limit Reading Result
HC(ppm)................................... 220 371 FAIL
CO(%)...................................... 1.20 1.50 FAIL
CO2(%).................................... 12.9
at 2642 rpm

HC (ppm).................................. 220 123 PASS
CO(%)...................................... 1.20 0.98 PASS
CO2(%).................................... 13.9


thanks for your help,
Lester


Modified by lelopez at 3:48 AM 8/16/2003

Blaze45

Repalce your 02, replace that cat... That should pass you...

Blaze

SCD16A6

try turning down your fuel pressure,if possible,and retard your timing.

sitrucjr

back a while ago when i had this generic header i bought off a friend on my car i failed the smog test,,,everythin else on the car was stock,,,i changed out the header for my stock exhaust manifold and took the test again and it passed,,,by the way i have a d15b2

lelopez

I know that the high HC content at low rpm's is possibly due to the car running a little rich. However, I ask myself, on a stock setup like mine, wouldn't the ECU throw a code if I was running rich like that? BTW, my 4-wire O2 was brand new when I did my swap about a year ago.

Could the cat be the problem even though it seems to work fine at high rpm's?

thanks,
Lester

fourthgenhatchB17

Are u using a stock P28? and yes at low rpm's it does appear to be running a little rich.

lelopez

Yes, I am running a stock p28, stock airbox, stock exhaust, and a lightspeed header. I checked my spark plugs, and although this may not be the best way, there is no evidence of rich fuel content.

I did have my timing advanced to the max so I've setted back to stock, but that's the only thing I can think of. Also, I've checked my O2 sensor and it is working fine.

One other thing, and please feel free to comment, by using the stock airbox from a 4th gen civic on a d16z6 I notice that the rubber hose from the box to the tb crimps up a little. Could this be limiting the amount of air going into the engine enough to cause the HC and CO content to be above normal levels?

thanks again,
Lester

spettinger

you need a good cat, and a bottle of "guaranteed to pass." i used two mustang cats off of a stock H pipe, and g.t.p. worked like a champ.

fourthgenhatchB17

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lelopez &raquo;</TD></TR><TR><TD CLASS="quote">Yes, I am running a stock p28, stock airbox, stock exhaust, and a lightspeed header. I checked my spark plugs, and although this may not be the best way, there is no evidence of rich fuel content.

I did have my timing advanced to the max so I've setted back to stock, but that's the only thing I can think of. Also, I've checked my O2 sensor and it is working fine.

One other thing, and please feel free to comment, by using the stock airbox from a 4th gen civic on a d16z6 I notice that the rubber hose from the box to the tb crimps up a little. Could this be limiting the amount of air going into the engine enough to cause the HC and CO content to be above normal levels?

thanks again,
Lester</TD></TR></TABLE>

I believe your "all the way" advanced timing will affect your low idle emssions. Set it back to spec &gt;&gt; 16+-2 degrees BTDC. Adjusting your timing back to where it belongs should make your car pass. About the air intake pipe (it should be from the SI model, not DX), i wouldn't sweat it too much unless its like almost ready to collapse totally...but other than that, u should be fine. Let me know what happens.

lelopez

Well, I failed the emissions test again, although my readings got a lot better.

1st test
HC................Limit: 220.................Reading: 371
CO................Limit: 1.20................Reading: 1.50

2nd test
HC................Limit: 220.................Reading: 258
CO................Limit: 1.20................Reading: 0.86

again, these were idle readings, I pass my high rpm test with flying colors.
So, since my first test I adjusted my timing back to stock, changed plugs and wires, cleaned intake system and that's about it.

I probably pass easily with a new cat, but being so close, are there any other suggestions so I don't have to spend $150 in a new catalytic?

TIA,
Lester

CLICC916

wow i wish i could score that well on low rpm testing...

went to the ref to do my jdm b16 (with ctr cams) and got:

15mph @ 2062 rpm
HC---------max:95-----------meas:220
CO---------max:0.58---------meas:0.61
NO---------max:726----------meas:2495

i have a faulty ecu and bad o2 sensors...maybe that's why

my guess is try to get another o2 sensor and run that "guaranteed to pass" stuff (remember to run a whole tank of that stuff BEFORE testing your car)...or get another cat...mufflertech in sacramento,ca sells them for 50 bucks

RedlineRex

my ef was a gross polluter at idle at first. then i swapped out the cat and the car just barely failed at idle (not longer GP). i went back the next day after i cranked up the idle to 900+ and then passed. just make sure that the cat is nice and hot, there may not be enough flow at idle to heat up the catalyst. --paul

lelopez

Marvel mystery oil? Pardon my ignorance but I'm not familiar with this product. Also, what lubricant you usually use to counteract the drying effects of the deatured alcohol.

BTW, I'm going to buy the product right now, pls let me know of the lubricant to see if I can test today. My deadline for passing emissions is Monday.

thanks,
Lester

fourthgenhatchB17

Do u have a fuel pressure regulator? If so, u can probably turn it down a little bit and maybe that will solve your HC problem. I used my FPR to my advantage when my EF failed too.

lelopez

no, unfortunately I don't have a FPR, this car is bone stock except for the z6 swap which is why I'm surprised it is still failing because of running on the "rich" side, at least at idle.

Also, one may suspect my o2 sensor, but this sensor is brand new from honda, yes, I spent their ridiculous $200+ for a 4-wire

thanks anyways,

Lester

nimbusnine

First you can idle your engine a lil' higher, I think the limit is 1200rpms to pass.
But 1000rpms should be good.
Second remember to run your car hard on the freeway to get the cat really hot so it can do its job before you test.
worst case scenario get a new O2 sensor
Ya I know "AGAIN". and maybe even adjust your valve lash.
hope this helps!! PEACE!!

fourthgenhatchB17

Time for a new cat. Probably 100-120$ installed.

lelopez

WOW this stuff works!!!...........I didn't put a lot of it in since I was a little afraid I'd mess something up, but went to the test today and passed,

HC.....Limit: 220......1st test.....371........2nd test......258........final test: 218
CO.....Limit: 1.20.....1st test.....1.50.......2nd test......0.86......final test: 0.75


Hey, I barely made it, but I don't have to worry about it for another 2 years, by then I'll have a new cat and should be able to pass without problem

thanks for all your help.
Lester