armerwandrer

I have a 1991 Honda CR-X with a first gen b16a swap. Car is converted to OBD1 and is running a P28 with a stock b16 map on Neptune. Currently there are no other mods on the car. The readings say that I am running rich. O2 sensor voltages are seem within spec. Not exactly sure what I should check now.

Here are the readings


They changed over to two stage idle test this year from the dyno system last year. Any help would be appreciated

zrickety

iTrader: (1)

Well your idle appears high, so check for a vacuum leak (hoses, gaskets). I would adjust the idle and check your tps voltage. Then do a tune up if you haven't, plugs, wires, filters etc etc and check the timing. Also, do you know that it's really a stock b16 map? Are there any other mods like a fuel pressure regulator? How is the exhaust and cat?

armerwandrer

the engine is stock except the obd1 conversion. I have already done a minor tune up. Plugs, wires cap etc. I checked for vacuum leaks spraying break clean on different areas of the intake manifold and such areas. There was no change in idle regardless of where I sprayed it. Also I'll have to check with the guy that did the map. He said that he was going to set the idle at 950 and I could adjust it from there. I have it adjusted all the way down. Also cat is an after market with about 10k miles on it. It is a magnaflow one that comes in the blue box with Mario Andretti on it.

I guess at this point I am trying to pin down if it is a car problem or a tuning problem. What else should I check?

4drEF

Your reading to HC and NO make it look like a bad ignition system.
Plugs, wires, cap, rotor.

armerwandrer

Plugs, cap, rotor, wires brand new Honda oem parts.

4drEF

I would guess against the O2 sensor being faulty since both CO and HC are both failing and they aren't super ridiculous far off either.

Ignition would effect all the areas you are failing, but it seems like you already have that covered.
.
The only other component that I know of that can cause failure in all these areas is the cat.
I don't know about the specific cat you have, but many aftermarket hi-flow units are junk.
Rather than using the expensive honeycomb core, they use cheap ceramic plates.
The plates do not even come close to working as well as the stock version.

Even if you had an new OEM cat, it has to be in operating temp to work properly.
It's best to drive about 10~20 min at proper engine operating temp and get the cat fully warmed up.

When you tested;
Did you have any additives in your fuel?
Did you drive a while before going to the test center?
Did you get right in and test? -or did you have to wait?
If you did have to wait, for how long and did you leave the car idling?
What octane fuel did you use? -you should use the LOWEST octane you can without making the engine ping. too high octane will result in unburnt fuel (CO).

Also, if it's super cold outside, it's probably not a great time to test since your exhaust may cool down quickly after you pull up to the test center.

zrickety

iTrader: (1)

What is the history of your distributor? I have one from ebay less than a year old and the coil failed. I drove it at least 2 months before it completely died.

hybridmiklo

that looks like a bad cat. The cat is supposed to keep store the o2 to keep the hc and nox down.

You shouldn't have any o2 left over. Plus your co2 is low. You want it as close to 15 as possible. Cat time. meow

vw eater

its a bad cat get a new one and retest there should be almost no o2

armerwandrer

I replaced the cat. It passed but I am reading 201 on HC with the limit of 220 at 2,500 rpm. Is there something could do to fix this or is this normal for a B16?

zrickety

iTrader: (1)

Unless the engine was rebuilt recently, that's probably as good as it gets. What kind of gas do you run?

4drEF

How many miles did you run your new cat for before testing?
Brand new cats need to be driven on a while to burn off contaminants inside and to get working properly.

armerwandrer

I welded it on at home. I then drove about 11 miles to the I/M place. Half freeway half surface streets. It then idled for about five minutes once I got there. I'm not sure if that is sufficient but that is how I did it. Maybe need to wait until next year when the cat has aged a bit to know for sure.