tone40

At 15 mph- max. 565 ppm measured 634 ppm (Failed). Passed at 25 mph- max. 522 ppm, measured 441 ppm. Oil temperature was ~ 235 F with a lot of idling and no airflow. Oil cooler fan manually turned on eventually, but oil temp was already high. ~80 F ambient.

Within tolerances- CO- At 15 mph max. .54%, meas. .24% At 25 mph max. .45%, meas. .33% and HC- At 15 mph max. 85 ppm, meas. 29 ppm, at 25 mph 67 ppm, meas. 34 ppm.

I have been using 87 octane fuel, so I thought that adding 91 octane would help. In fact, it made it worse. NO is now at +1000 ppm at 15 mph. This was done on a diagnostic test (Not a re-test). Cooler oil temp (~210 F) and air temperatures.~ 70 to 75 F ambient. Oil cooler fan manually turned on from the start.

It has been ~9K miles and 2 years since my valve adjustment and spark plug replacement. ~23K miles since my cap and rotor replacement.

Any comment on a diagnosis? Would cap, rotor and air filter replacement bring the NO readings back in compliance?


Thanks.

tone40

If replacing the cap and rotor, should I insist on Bosch or is Beru acceptable?

Amber Gramps

I can occasionally see smoke at start up after a long sit and still easily pass.

Here are my results without a cat:
https://rennlist.com/forums/5505616-post9.html

ricster

Glad I dont live in Kalifornia

rusnak

I would make sure that the "bridge to ground" wire under the driver's seat is attached. You may need to borrow a new cat, and it'll pass.

tone40

I checked under the driver's seat and did not find any loose connections. I did not see a wire that was only attached to the body structure as a ground there.

Something I did notice: the O2 sensor has a semi-circular shield around the metallic portion of the sensor. I assume that someone installed this to reflect heat from the nearby cat. I wonder if this is restricting airflow into the sensor.

The cat has ~35K miles. The O2 sensor has ~75K miles of service. The Bentley manual gives a maintenance interval of 60K on the sensor.

I checked for missing hose connections and found they were all intact. I will do more investigation tomorrow and see if I can find anything that is causing the lean condition (Leading to high NO readings).

ricster

Tone40,

Just for an FYI and everyone here on the site living in Calif, you can pay a lawyer out of Montana to get your car registered and avoid this silly smog test and you dont even need an address there. If you look in the back of the dupont registry I think his ad is there, I know someone who did it and it works like a charm.

Lorenfb

1. U.S. DME ECM
2. O2 sensor is hooked-up & working
3. No so-called 'performance' chip

rusnak

Tone, you may need a new O2 sensor, but it doesn't seem that the car is running that rich. The bridge to ground is a separate connector for a brown wire that leads into the dme harness. I posted a pic in the Redline Autotech forum. It is listed in Bentley as well. Look for a white connector for a single wire.

A tuneup with new cap and rotor may help.

Ed Hughes

Interesting, I'd not heard of this before.

tone40

My attempts to correct the high NO readings: Replaced air filter. Added fuel injection cleaner. Used 91 octane fuel. Had the CO level adjusted by a mechanic. No change in readings.

Smog test mechanic: Check readings early in the AM so that the air fuel rtaio is richer. (High NO readings are from lean and high cylinder head temperature conditions). Maintained air flow in front of oil cooler.

The final resolve was a temporary switch on the catalytic converter. A previous owner replaced the catalytic converter to a non-OEM variety (I only learned this after the initial smog test). My indie said that the catalytic converter is the wrong one and too small as compared to a Carrera cat. My O2 sensor is operating correctly.

The car passed with flying colors. My wallet is much lighter after this experience.

Catalytic converter replacement alternatives are even bigger dollars. I have to go through the switch or a cat replacement to pass smog every 2 years.

vracer

Cal. residents, you may want to roll the dice on this, but understand that it is a roll of the dice. The state of California (and every other state for that matter) does not like residents evading taxes and regulations. If you get stopped, and your DL shows a Cal. address, you will have some 'splainin' (Sorry Dezi) to do. You may get away claiming that the car lives out of state at your second home, but if the same cop notices (Are these car noticible?) the same car again - trouble for ficticious registration.

theiceman

hey what happened to our community cat idea ,we were gonna mail a cat around North America to those who needed it . I thought the idea had merrit

tone40

had incorrect limits inserted or if the limts got more strict. 2 years ago the NO limit for 15 mph was 807 and for 25 mph was 746. Now that are about 200 ppm lower (565 and 522). It does make sense that BAR would lower the limits without a required change in vehicle emissions equipment?

Steve Weiner-Rennsport Systems

Aftermarket cats have been problematic for many years and generally speaking, will not install one on any car that needs to be smog tested, just for these very reasons.

With few exceptions, they are the "Road to Perdition".