SMOG Failed - High CO on Low Speed Test - Ideas?

[spyerx]

Any pointers? Car has passed every year w/o issue. stock cat, chip, etc. Motor is stock, plugs new, wires new, cap rotor new, seems to run OK...

ideas before i bring to my tech?

Last time almost all the measures are very very close except low CO, which time was .38

[Nick Triesch]

Run some techron a week before test, Have clean new oil in car, 40 PSI in back tires!! ( less drag ). Fresh valve adjust a must! And most important, drive the hell out of it right before test! Make sure it is hot. Sometimes I leave my car running if there is a bit of a wait for my test. One more thing, all shops can do a pre test that does not count to see where you are. Cost some extra bucks but I always do it. Keeps you from being flagged!

[Joe Bob]

Cat or 02 sensor despite what anyone says, they wear out. If CO is high the HC will be low. Take to an independent have it put on a sniffer. Go from there.

[DRACO A5OG]

Where you located OP?

[spyerx]

Originally Posted by DRACO A5OG

Where you located OP?

Just over the bridge from you in Belmont shore.

The car passed last year and all the numbers look better this year except the low speed co. That is the only one that failed. Oh and I have to get it done at a star station for some reason this year.

Car was hot, o2 sensor I'm unsure of age, pin 10 is connected, chip is stock, cat is original, car Has 88k miles and is in good tune (or so I thought).

I'm thinking o2 is cheap to try first.

Anyone know a shop with a sniffer so I don't need to keep doing the tests?

[86 911 Targa]

Replacing the o2 sensor fixed my same identical issue.

Gerry

[spyerx]

Here are the results of the test from last year (I bought car a year ago so this test on sale) for some reason I had to smog this year as I guess that was the normal cycle for every 2. Looking at the results on ca dmv site it's passed every year for 20 years.

You can see all the results are nearly identical, except no is way lower this year and co is a lot higher but only on the low speed test.

What you say clogged up o2 sensor??

Result from 6/2015:



Result from 7/2016:


PASS Result from 7/2016:

[DRACO A5OG]

I am in RPV, if you like we can meet or you can come over and I can check your AFR with my LM2.

You need to get her at 194F to test AFR properly.

PM me.

[Joe Bob]

My bet is on the cat....

[86 911 Targa]

^^^^^
I went from this-


^^^^^
To this by just replacing the O2 sensor.

Easy-Peasy.....

Interesting, your CO Max values are less than our M/Y 86.

Best,

Gerry

[Joe Bob]

Crap 50/50 chance of nailing it.....oh well glad you got it done. Did the 02 sensor come out hard and crumble in your hand? Make sure you put anti seize on it. BTDT.

Edit: Gotta read the whole thing, wasn't the OP posting...anyways good luck it's one or the other. There is a cat for sale in the classifieds even tho it is technically illegal to sell a used cat, but who cares...%^)

I have a dead cat out front but it is starting to smell....bada bump....

[DRACO A5OG]

M and G, you were both correct.

We found O2S had a severed black line at the connector but that only activates the heating of the O2S, but he will replace it anyways. The Sensor itself seems to work when we disconnected it and reconnected it.

Then we checked the AFR, BINGO. it was reading super rich 13.5 with stock chip and brown wire connected with cat on. So the cat was being over worked and could not clean the exhaust adequately.

Found the AFM was replaced but we thinks it was tampered with at the dealer and resealed with the press in cap. I had a spare AFM already tuned to 14.7:1

Swapped it, Voila 14.7, OP reported smoother idle and driveability even for a stock chip, it is a 89 so it should be nice and smooth. Set base idle to 880 RPMs, found it at 800 probably compensating for the bandaid fix.

OP is going to remove the cap on his AFM so we can properly adjust the AFR but he will use my AFM to go get her smogged.

Break a Leg OP!

[Joe Bob]

Woohoo, score one for the win!

[spyerx]

Ah need to pass the sniffer still, in process of swapping O2 now.
Then drive her hard and see if I can find one open today, little work to clean up my meter + drill out the adjuster.

HUUUGEEE Thanks to Draco!!

[Bob Kontak]

Originally Posted by Joe Bob

Woohoo, score one for the win!

Yepper!

You were spot on and DRACO performed the miracle.

God bless Pelican Parts Tech Forum.

[spyerx]

My 02 sensor came out w/o issue. Had anti-seize on it. New one in. Airflow Meter is cleaned up, cap removed, so we can get mine setup properly. Oh, Draco had me measure how many "turns until closed" and it was 2.5, so a rich setting I believe.

The sniffer test will have to wait until tomorrow, but car seems to be running much better and the tailpipe smells substantially cleaner than before.

FINGERS CROSSED!

[Joe Bob]

Shouldn't be a problem on a DME car. Fix the bits that be broken and it should all fall in line. JUST DO NOT go to the smog weenies unless they will do a pretest w/o hooking up to DMV's modem. YES they still use a modem.

[Quicksilver]

Originally Posted by DRACO A5OG

. . .

Swapped it, Voila 14.7, OP reported smoother idle and driveability even for a stock chip, it is a 89 so it should be nice and smooth. Set base idle to 880 RPMs, found it at 800 probably compensating for the bandaid fix.

. . .

The low idle should be forced to 880 by the DME unless the ICV is pooched (which doesn't seem likely seeing as it is otherwise running good.)

I'd check and see if it ended up with an early DME with an earlier chip with the 800 idle. That 89 should have the last and greatest chip in it.

[DRACO A5OG]

That is what I thought too, but base idle was set way too low, probably to compensate for the fuched up AFM settings. In any case, OP will clean the ICV, just to be safe, we found his AFM full of oil.

OP said PO had over filled the oil on many occasions at least when OP bought it from PO.

Over all the car was super clean.

[spyerx]

And we have VICTORY!

Summarizing:
Draco felt car was running rich
He showed me (and did most of it!) how to do a quick smoke check to check for any leaks. None found.
Got car hot and found it's idle AFR was very rich
My Airflow meter was plugged, so he was kind enough to let me borrow a spare
Put that in, AFR was spot on (and car ran better!)
I swapped in a new O2 sensor, we found one of the wires CUT
Got car nice and hot, beat on it a bit, and took it in. Tech hooked it up to his sniffer prior to the official test and said car looked good and felt it would pass.
Car is running MUCH cleaner across the board and compared to last year.

So the issue:
AFR set to too rich
Bad O2 sensor (probably)

Now I get to swap my parts back in and adjust my AFM (plug removed).

Can't thank Draco and Pelican enough!!!!

BTW: My car is an early 89 I think, production date mid 88. So unsure of what I have in there for an ECU.