1989 323 failed emissions

[swivel]

Hey all,

Well it was time for my project 323 to go through the sniff test today.
The final result: FAIL

The paper reads this:
GAS STANDARD READING RESULT
NOx 1657 1661 FAIL
HC 212 114 PASS
CO% 1.20 .78 PASS

So it failed NOx, but not by very much at all. 2 years ago when it got sniffed, it barely eeked by the NOx test.

As some of you may have read, I've recently done a pretty major rebuild on this car. I've been told that running hot can cause NOx gas, but it has a new t-stat and radiator. Timing might be an issue, and I'll check it again, but I was pretty careful to set it dead on what the shop manual says.

Really, though I'm guessing at this point, I'm just looking at a new cat, which is fine. I recall a similar situation with my old jeep, where after I replaced the cat, all the numbers came down to single digits (the look on the testers face was priceless).

So, my plan is to replace the cat and run it through again. Any other suggestions? Note, I'm not a fan of throwing additives in to try and "fool" the test, I'd just assume fix it right and not have to worry about it next year.

[hobie237]

Back off the timing and try a new oxygen sensor are the most common "free.cheap first tries" that I know for high NOx.

[hobie237]

Any luck?


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[swivel]

Not yet. I haven't had a chance to dig into it, plus I'm going to be out of town this weekend. I have something like 45 days to get it reinspected, so I'm not under any real pressure. I have my attack planned for next Friday. I plan on a new O2 sensor, and to retard the timing. Actually, the distributor shaft o-ring is seeping a little oil, so I'll probably replace that first, and just set the timing once.

I'll let you know how it goes.

[swivel]

Well, on Friday I dove into the 323 and did the following:

Replaced Valve Stem Seals
Replaced Distributor Shaft O-ring
Replaced O2 sensor
Adjust ignition timing from 2 degrees BTDC to 3 degrees BTDC
Oil Change
Rotate Tires
New rear wheel cylinders
New Left Rear wheel bearing.

I have to say it drives a lot better now -- It honestly feels a little stronger and the power delivery is definitely smoother.
The added bonus to all the other work is:
1) Both rear wheels help stop the car now (yeah, I actually failed safety for the LR doing nothing).
2) The dull roar from the bad bearing is gone.
3) The puff of blue on cold start is gone.

Unfortunately, by the time I buttoned everything up, the inspection station was long closed, but I'll run it through this coming friday.

You know this started out sort of as a "if I can do it why not" project, but is slowly turning into a very nicely maintained 20 yr old car.

--Jason

[swivel]

Today was the big day:

We went through inspection and passed!
Although if it were a report card, it might say D-

The NO compounds dropped to 1653 -- hardly a winning score, but 5 ppm below the failure threshold, so I passed....

Maybe I'll be due for a new cat in 2 years when it gets tested again ;)

[hobie237]

Hey, you passed, that's the important thing.

[swivel]

Hey, you passed, that's the important thing.

Funny, my parents never seemed to buy that argument when I was in school ;)