DelSolDon

I am thinking about changing my O2 sensor because I have tried to pass good ol' e-check twice now with no luck. My NO is reading way too high and I can't seem to find out why. I own a 93 del sol with a obd1 jdm b16a swap in it. I have fairly new oem ignition components, stock FPR, stock injectors, etc. About the O2 sensor, which should I buy for, the 93 del sol si (what the car is), or a 95 del sol vtec (what i order parts for when i need engine related parts). I looked on oxygensensors.com and they had 2 different part #'s for both cars. Is this maybe my problem that I have been running a 93 del sol si (d16z6) O2 sensor with a b16 motor? I thought they were the same sensor. Any help on why my NO levels are so high would be great.


Modified by DelSolDon at 10:27 PM 3/20/2005

DelSolDon

could my high NO levels be because of my intake leaning my car out? should i consider an adjustable FPR to raise fuel pressure a little?

DelSolDon

can anybody tell me what my fuel pressure should be with i/h/e and stock internals on my b16? searched, but found many diiferent answers.

hatchi

have you checked the catalytic?? i have o2 sensor if you want to purchase

Hybrid96EK

Dude. No.

High NOx levels = high cylinder temps. Adjustable fuel pressure regulators are not legal (at least in Cali) for emissions. Your fuel pressure should be set to stock settings, nothing more, nothing less. 38psi with line on, 48psi with line off.. Approx. I don't think changing the O2 is going to help your problem either. If the car WAS running lean like you suspect, the CO% would be greater then 14.7. Post the whole sheet of results.

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">High NOx levels = high cylinder temps</TD></TR></TABLE>

Have you checked your ignition timing? Advanced timing will typically cause higher cylinder temps which means higher NOx levels too.

AutoXer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">Dude. No.

High NOx levels = high cylinder temps. </TD></TR></TABLE>

Exactly. This could be due to running lean, or poor cooling. There are other factors, but these should be checked first.

DelSolDon

first test: (car sat for about a week, then drove for a while that day, had sta-bil in the tank)

<U>reading</U> / <U>limit</U>
HC 147.3ppm / 147.0ppm fail
CO 0.59% / 0.82% pass
NO 2907.4ppm / 1072.0ppm fail
CO2 14.78% / N/A

second test: (new tank of gas)

<U>reading</U> / <U>limit</U>
HC 118.2ppm / 147.0ppm pass
CO 0.56% / 0.82% pass
NO 2227.7ppm / 1072.0ppm fail
CO2 14.61% / N/A

so what ya'll think? by the way, in ohio we don't have any visual engine inspection so i would be ok with an adj. FPR.

DelSolDon

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

Have you checked your ignition timing? Advanced timing will typically cause higher cylinder temps which means higher NOx levels too.</TD></TR></TABLE>

yea, timing was the first thing that i checked when i got home.

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DelSolDon &raquo;</TD></TR><TR><TD CLASS="quote">first test: (car sat for about a week, then drove for a while that day, had sta-bil in the tank)

<U>reading</U> / <U>limit</U>
HC 147.3ppm / 147.0ppm fail
CO 0.59% / 0.82% pass
NO 2907.4ppm / 1072.0ppm fail
CO2 14.78% / N/A

second test: (new tank of gas)

<U>reading</U> / <U>limit</U>
HC 118.2ppm / 147.0ppm pass
CO 0.56% / 0.82% pass
NO 2227.7ppm / 1072.0ppm fail
CO2 14.61% / N/A

so what ya'll think? by the way, in ohio we don't have any visual engine inspection so i would be ok with an adj. FPR.</TD></TR></TABLE>

CAT. Not O2.

DelSolDon

^^^really? i just replaced it maybe 2 years ago. it is a catco hi-flow cat though, would that have anything to do with it? i passed last time with it on.

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DelSolDon &raquo;</TD></TR><TR><TD CLASS="quote">^^^really? i just replaced it maybe 2 years ago. it is a catco hi-flow cat though, would that have anything to do with it? i passed last time with it on.</TD></TR></TABLE>

Well... prolly not then. Maybe a missfire, carbon build on the cylinders... done a valve adjustment recently? I'm not an expert though. Forget the cat though. I was prolly wrong on that since its just been replaced.

DelSolDon

just did a valve adjustment. i ran seafoam through the brake booster line since the last test, so carbon should be ok now. a buddy of mine suggested running a step colder plug and running 87 octane instead of my usual 93. but now, i have a different problem, i was coming home tonight and i started getting this loud clunking sound. it sounded like it was moving the same speed of the wheel and slowed and sped up with the speed of the wheel also. it would stop when i gave it gas and when i braked, but would start when i coasted. so, i figure it is one or more of my CV joints, right? i have replaced my axles not too long ago, but i do have my sol lowered so i could be.

VTEC Sol

You're gonna want to buy the O2 sensors for the B16A Motor. I'm having the same problem as you right now. I'm in the process of getting the money to fix it.

Train

yeah, high NOx levels are due to high cylinder temperatures. running 87 octane isn't a bad idea. yeah, it will set your knock sensor off and retard timing, so that might bring temperatures down a bit, but you should be able to pass without having to cheat the system. a hi-flow cat isn't really meant for reducing emissions. most are practically a straight pipe with the charcoal type stuff between the pipe and the housing, so most of your air goes straight through, rather than the gases being absorbed, burned, filtered, etc. if you put a stock cat back on, you would probably see a positive difference. i'm not sure if obd1 hondas have a 2 or 3 way cat, but ...well, if its honda, its prob 3 way. so yeah, a stock cat would probably do you good. see if you can get a hold of an ITR cat. it'll flow more than your stock one, but is still good with emissions. the inlet and outlet are 2.25".

what was your O2 level btw?

here's my numbers from my (totally stock) '97 LS w/ 175k miles:

<U> @ IDLE</U>
CO: .002
CO2: 15.00
HC: 0
O2: 0
AFR: 14.70
NO: 0

<U>@ 2500</U>
CO: .043
CO2: 14.99
HC: 0
O2: 0
AFR: 14.75
NO: 7

w00t! not bad for a high mileage engine. i left out a few other gases that aren't as important. those figures weren't done for inspection reasons. just for fun really. of course, not all cars will have figures quite like the above, especially ones that are modded, but the EPA is cracking down. my figures were worse at 1500 rpms too, btw.

EDIT: an O2 sensor only reads oxygen in the exhaust. changing it won't do anything, but you will have wasted money doing so. your O2 sensor won't change how high your NO levels are. it doesn't know, and it doesn't care. it measures oxygen in the exhaust somehow, it somehow makes a very small amount of voltage out of it, and sends that voltage signal to the ECU, and the ECU determines whether to add or subtract fuel based on that signal.



Modified by Train at 4:26 AM 3/22/2005

AutoXer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DelSolDon &raquo;</TD></TR><TR><TD CLASS="quote">^^^really? i just replaced it maybe 2 years ago. it is a catco hi-flow cat though, would that have anything to do with it? i passed last time with it on.</TD></TR></TABLE>

This could be part of the problem. Hi-flow cats just don't work very well for reducing the emissions.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Train &raquo;</TD></TR><TR><TD CLASS="quote">EDIT: an O2 sensor only reads oxygen in the exhaust. changing it won't do anything, but you will have wasted money doing so. your O2 sensor won't change how high your NO levels are. it doesn't know, and it doesn't care. it measures oxygen in the exhaust somehow, it somehow makes a very small amount of voltage out of it, and sends that voltage signal to the ECU, and the ECU determines whether to add or subtract fuel based on that signal.
</TD></TR></TABLE>

You have some right and some wrong information in there. Yes, your 02 will not directly measure and change your NO levels, but having one that doesn't function properly can lead to high NO levels. This is because, it does, as you say, change fuel levels in the combustion mixture; which is the key.

High cylinder temps are the result of a lean condition, and if you have a bad 02 sensor, it's response time slows, and doesn't deliver the optimum fuel level. This definitely leads to lean burn conditions and high NO in most cases, and should be the first thing to be checked. The next would be cooling, but since he has a high flow cat, I would assume that would be the next culprit.

Train

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EX_AutoXer &raquo;</TD></TR><TR><TD CLASS="quote">
You have some right and some wrong information in there. Yes, your 02 will not directly measure and change your NO levels, but having one that doesn't function properly can lead to high NO levels. This is because, it does, as you say, change fuel levels in the combustion mixture; which is the key.

High cylinder temps are the result of a lean condition, and if you have a bad 02 sensor, it's response time slows, and doesn't deliver the optimum fuel level. This definitely leads to lean burn conditions and high NO in most cases, and should be the first thing to be checked. The next would be cooling, but since he has a high flow cat, I would assume that would be the next culprit.
</TD></TR></TABLE>

true, if it is not functioning properly, it can misread the oxygen level which will give the ECU an incorrect signal. if the ECU leans out the mixture, it will raise temps and increase NO. if it richens it, it will cool the temp slightly, but you'll get more HC and CO. so it could go both ways. the fact that he had too much HCs on the first test and still had lots of NO made me think his O2 is ok. i might have been quick to jump to that conclusion, but i'm betting his O2 sensor isn't the problem.

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EX_AutoXer &raquo;</TD></TR><TR><TD CLASS="quote">High cylinder temps are the result of a lean condition, and if you have a bad 02 sensor, it's response time slows, and doesn't deliver the optimum fuel level.</TD></TR></TABLE>

High cylinder temps and lean conditions go hand in hand, however, a slow responding O2 sensor usually creates a richer condition. This is the reason why a lot of aftermarket O2's don't jive well with Honda ECU's - they don't switch fast enough out of the box.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EX_AutoXer &raquo;</TD></TR><TR><TD CLASS="quote">This could be part of the problem. Hi-flow cats just don't work very well for reducing the emissions.</TD></TR></TABLE>

Agreed here.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DelSolDon &raquo;</TD></TR><TR><TD CLASS="quote">yea, timing was the first thing that i checked when i got home.</TD></TR></TABLE>

What was it? Might help to be on the low-end of the range for emmisions - like around 14*.

DelSolDon

the timing was a little high, so i adjusted it down a little. i haven't tested since then so i dunno if that was it.