Skryblz

I went and had my 95 LX D15B7 e-checked and it barely failed hydrocarbons my HC ppm was 174 limit 167, NO was 2845 ppm limit 1240, and CO% 0.76 limit 0.94.

2 years ago my numbers were 23.8 HC ppm, 230.2 NO PPM, and 0.03 % CO; super clean.

What could have changed that much?

I was about to order basic tuneup stuff plugs, wires, cap and rotor to start, but the wires cap and rotor were all replaced Feb 2014 and I put only 8-10k miles on since then.

Plugs are over a year old so I'm getting new ones anyways.
Air intake was changed to an ebay cold air one w/an AEM filter.
Catalytic converter was replaced in 2011 with a Magnaflow one (~40k miles), haven't cleaned the EGR valve for a while.
Lots of fairly new parts in general (whole new distributor ~30k miles, most gaskets, fuel filter ~40k miles ago)
Both o2 sensors were replaced w/Denso OEM ones ~20k miles ago.

Before I go ordering parts I don't need, what do you think I should check first? I need to adjust the valves too I never have and they are noisy, would that affect the numbers?

Former User

Do a full ignitions system tune up and then go from there.

TomCat39

The D15B7 doesn't have an EGR valve, that was only on the D15Z1 VX motor in the 92-95 series.


Bah!, see slomofo already mentioned you don't have an EGR.

Skryblz

I'll have to see on Monday if the tester workers can do that for me thanks for the tip.
Rotor and cap were pretty scorched on the tips, spark plugs are all fairly white though with some minor orange on parts of some.
Rotor+Plugs
https://i.imgur.com/HL9haqz.jpg
https://i.imgur.com/5wtBDc4.jpg

The distributor is set directly in the middle with no adjustment right now. I had to replace the entire unit after it died completely a few years back and that's where my OEM was so I didn't change it.
Timing was set ~20k miles ago had to replace the head gasket so did the whole job, new belts, water pump, etc. The exhaust valve seals in the head were replaced by a machine shop at that time.

I've been meaning to change the fuel filter in the gas tank as it probably never has been (158k now).

Exhaust is all sealed up and quiet, manifold and header gasket were replaced same time as the converter so 2013.

I still ordered cap+rotor+plugs+wires since they didn't look too good, will be here Sunday Didn't see any good lips though

Former User

After you install the ignition parts, be sure to adjust the ignition timing to spec as well. There's a diagram in the FAQs sticky.

Any CEL codes?

Skryblz

No CEL's at all and the light works.

Parts were a little late to come in, and my timing gun had a burnt out bulb (old Sears one), but I finally had everything replaced and rechecked.
All in all I did OEM cap + rotor, new NGK plugs + wires, in tank & pre fuel rail fuel filters, oil change w/seafoam, techron fuel system cleaner, adjusted the timing (was off a decent amount), and did the valves (lots of ticking resolved).

Went to echeck, and failed again. Barely dropped the HC and my NO went up by 500+ ppm. HC was 167.3 ppm limit 167 (was 174), CO 0.64% limit 0.94 (was 0.76 last test), NO 3376 ppm limit 1240 (was 2845).

I am getting the receipts together for a waiver so no worries the next few years.

I want to know how I went from 1/6 of the limits (23.8 HC, 0.03 % CO, and 230.2 NO in 2011) to failing completely with no real driveability changes or issues.
And of course find the real reason I failed. My o2 sensors have less than 30k miles each (denso) and the cat has ~30k (magnaflow), all done in 2011. I can't think of what else it could be.

Former User

Post the complete emissions sheet (remove personal information).

I think your cat is dead because the engine ran rich. But don't replace the cat until you figure out why the HC is high.

Is there a crack in the exhaust manifold near the O2 sensor?

Did you check the fuel pressure and FPR, or for a stuck open fuel injector?

Former User

I'm open to discuss, slomo, unless you're just on a troll mission.

HC in the exhaust is quite high (rich), despite being close to passing. I'm not ignoring the exceptionally high NOx, so there must be additional issues. My initial goal was to attempt to rule out ignition system misfire as the cause of the high HC. For example, the age of the plug wires was not mentioned, and ignition system misfire due to poor maintenance is probably the most common cause of high HC.

Former User

Post the link to this head gasket thread where I was trolling.


So why did the "not very high HC" fail to pass HC? Answer - because it's high.

How is this^ example even relevant to the OP's issue given that a vacuum leak would also cause a major idle problem?

Former User

Changed your mind along the way.

Former User

For the benefit of new members who come across this tech thread, let's establish some facts before we proceed further. slomofo is one of the most highly accomplished trolls at Honda-Tech, and has been for many years. He takes great pride in his troll prowess. Even during this thread, slomofo is almost surely trolling multiple members, and I know for a fact that he is currently attempting to troll at least one moderator, likely more.

Which means rich.

Yep, running rich.

Which after ECU compensation becomes rich. Also irrelevant here as there's no mention of a high or hunting idle in this thread.

All nice ideas, but I thought you were confident in having the issue all figured out? Are you beginning to question yourself?

So post the link showing me trolling.

Dorkenheimer

For what it's worth, here's mine. I know I'm running rich. Interested to see if this thread can come to a solution.

Edit: omg, my phone finally didn't turn the picture sideways. Sweet success!

Former User

^There's a statement about the failure relating to low idle, but an 880 rpm idle seems high.

The O2 levels are high, suggesting an exhaust leak near the O2 sensor or a vacuum leak.

Dorkenheimer

Yes, I am idling high. Don't mean to thread jack.

Former User

Set the idle speed to spec, though the high O2 remains a concern.