Severely failed smog test - AZ ideas?

CrossT · 03-30-2005, 12:53 PM

My car is an 86 3.2 which is stock except Magnacor wires which have been in for 2 years. It runs fine [best ever].

reading max allow
---------- -------------
HC loaded [30 mph]
217 220 pass

HC idle
1712 220 fail

CO loaded [30 mph]
3.30 1.20 fail

CO idle
5.86 1.20 fail

holy ^%$* !!

Never came even close to failing in any prior year. I have fairly recent plugs [Bosch copper] and gapped them correctly. Only recent work was valve adj. While I was adjusting the valves I broke the little shield on the O2 sensor and removed the shield thinking it was a non-issue [ ? ]. The test itself took way longer that any I have done before.

Obviously something has really gone awry

Any ideas what to start in on before I go to the wrench and $$

thx
todd
86 coupe

FrayAdjacent911 · 03-30-2005, 12:57 PM

With the HC Idle being high, I'd think your mix may be on the rich side.... But I'm pretty n00b to the p-car, so I'll defer to the experienced guys who will respond any second now.

Any second.

Just about...

... now...

CarreraS2 · 03-30-2005, 01:18 PM

When my BMW failed with high HCs like that, it was the 150,000 mile cat that had finally gone bad.

CrossT · 03-30-2005, 01:30 PM

My car's cat is likely the orig and the car has 176K on it. The eng was top-rebuilt at 150K.

Would a bad O2 sensor connection/disconnected O2 sensor produce this type of reading?

todd
86 coupe

FrayAdjacent911 · 03-30-2005, 02:07 PM

If your cat is the original with THAT mileage on it, I'd be looking at replacing it, and I'd probably replace the 02 sensors just for good measure.

Joeaksa · 03-30-2005, 02:24 PM

Moving to Casa Grande, or just out of Pinal County, is a very good option!

Glad I have a house in Prescott!

JoeA

air-cool-me · 03-30-2005, 02:53 PM

Quote:

Glad I have a house in Prescott!

its a slllloooowww place....

stefang · 03-30-2005, 03:03 PM

Quote:

Originally posted by CrossT

Would a bad O2 sensor connection/disconnected O2 sensor produce this type of reading?

todd
86 coupe

Having just gone through inspection (and failed) with my O2 sensor disconnected (don't ask), I can tell you that no, it does not. CO actually goes down, HC largely unaffected, NOx though spikes.

Stef

CrossT · 03-30-2005, 06:03 PM

Could my recent valve adjustment cause this? I have a couple of valve that tick a little more than I would like, but it was my first valve adjustment, so I am pleased with the overall outcome. The car runs great - and notably smoother than before the work.

just grasping . . . before spending

todd
86 coupe

jriera · 03-30-2005, 06:57 PM

Todd, if it makes you feel any better I went for my smog registration inspection on Friday, results:

HC low 4105 (220 pass)
HC high 7341 (220 pass)
CO% low 6.46 (1.20 pass)
CO% high 6.32 (1.20 pass)

I win!! I win!!

Obviously the car did not pass (where are the 'see no evil' smog inspectors?) .... Off to the shop tomorrow.

Joeaksa · 03-30-2005, 07:09 PM

Quote:

Originally posted by air-cool-me
its a slllloooowww place....

Its so slow that they do not do smog testing either! There are benefits to living out in the country!

JoeA

air-cool-me · 03-30-2005, 11:31 PM

yes! all the moving chicanes(sp) called "trucks"

CrossT · 03-31-2005, 07:22 AM

i have a new cat on the way. also, I will lean out the AFM spring a couple 3 or 4 notches [i.e., tighten] and head back down to the station next week. it ought to be squeaky clean then . . .

thx
todd
86 coupe

Thomas Owen · 03-31-2005, 08:34 AM

Todd, just you know, I lived in Tucson and passed every year without a cat. The first year I had a bypass pipe, and then went to the euro pre-muffler from Fabspeed. Both setups used the O2 sensor. You will probably pass by getting the old cat out, whether you put on a new one, or a bypass pipe.
One other thing - when on the rollers, select a gear real quick that allows the engine to run at a nominal rpm.
Good luck -

CrossT · 03-31-2005, 08:41 AM

Thomas

You hit on something I though of after the failed test. I ran the car at 30mph in 2nd which got me about 2800rpm. Like you said, I realized after the fact I should have dropped it quickly into 3rd or 4th and ran at something way less.

todd
86 coupe

robertb · 03-31-2005, 03:03 PM

you guys in Tucson are lucky, in Phoenix we have to let the technician drive it on the rollers.

Scooter · 03-31-2005, 03:18 PM

There are enough people on this site that have switched out there cat for a bypass of some sort, I am sure someone has a cat he could borrow for the test?

Barrpete · 03-31-2005, 04:21 PM

Todd,

I don't think you're failure was because you were still in first gear. I say this because you're idle readings are way high. I'm in Tucson also and just bought my first 911 - an 86 3.2L coupe that is completely stock. I did the emissions test right after I bought it and my readings were:

HC loaded [30 mph]
73 (220)

HC idle
57 (220)

CO loaded [30 mph]
0.59 (1.20)

CO idle
1.06 (1.20)

I would check your O2 sensor. It's supposed to sense the oxygen in the exhaust to make sure there's enough for the cat to convert CO to CO2 and to burn the excess hydrocarbon. If it's not working it could cause your problem.

By the way, who do you use in Tucson to do your wrench work?

John

CrossT · 03-31-2005, 05:42 PM

John,
Your car must leave a trail of soap bubbles . . .

The O2 sensor is about 20K old, but I suppose it could be defective. I am beginning to think the issue may well be with my AFM. Once I get the new cat and adjust the spring in the AFM, and get it retested, I'll post results [I hope passing]

The only wrench I've used is Redline Service. Chuck does seem to know his stuff [not cheap though]. I have also heard that Radmacher is good, but haven't been there. If you need extra hands or want to compare/swap things for parts testing, let me know.

todd
86 coupe

Barrpete · 04-01-2005, 06:32 AM

Todd,

I have to admit I was a little worried before the test since the PO had it registered in Flagstaff & didn't need emissions.

I only mentioned the O2 sensor since you said you broke a shield off of it and if that did indeed damage it, it could cause your problem. In the grand scheme of things that seemed to be a cheaper thing to replace than the cat or AFM but certainly both of those could be the problem as well. (Of course now I'm really stretching my limited expertise - particularly being a Porshe newbie. ) Good luck - I know what a hassle it is when you fail emissions.

Thanks for the tip on the shop. I used European Auto Tech when I first bought the car for a valve adjust(~$400) & a few other minor fixes. No complaints about the work but also not cheap.

BTW here's a pic of my car so you'll know if you see me around town.

Just look for the trail of bubbles!