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I think maybe it came out of a cvt or something that didn't need the extra pep. But yes, now I'm just crossing my fingers. I got a quote today for $100 to chop in a new cat, plus whatever the cat costs if I buy it so just under $200 for that which is more doable then $500.

 
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I'd wait and see if it sets a cat code again or a few times in a row before pulling the trigger on the cat.


It would have been interesting to see what scanner data looked like with the other injectors in it.

 
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Unfortunately I just have a low grade scanner so I can't figure that out. I am curious though if the injectors were smaller or larger then the ex injectors.

 
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Update: Well I passed emissions, so atleast for MD regulation I am fine. No code since changing the injectors so I'm waiting in anticipation for it to pop back up.

 
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Update: cat code has come back. I've reset it about 5 maybe 6 times and it keeps coming back. Will anyone vouch for a specific cat lasting longer then 2 years and not setting off a code after that time?

 
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Factory cat of course is best
California CARB approved would be next best (check warranty coverage).

I don't even bother to offer any other choice to customers. If they want cheap they can go be pissed at someone else when it fails.

Do not look at post #7 in this thread by bsmiley.
This is illegal and violates all kinds of laws. *hugs a tree*

 
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I'm a simple minded guy. I think of it as a $27 enhancement to the vehicle. New Denso secondary sensor $24 (Amazon) and $2.83 in a capacitor & resistor. Its an 01. The loss value if I get wrecked is close to rock bottom.
Anyway, its a ULEV and the low pass filter just keeps out anomalies that were erroneously tripping the CEL.
I used hi temp RTV after my component soldering and then put new heat shrink over the whole thing. I don't think anyone is ever going to notice. Fingers crossed it keeps the CEL light out.
I like the old cars, they run great and enhancements can be easily done. Insurance, taxes and parts are cheap. Maybe I'll keep it for 10 more years, its fun to drive, as fast as a Porsche in rush hour traffic, too!

 
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Just an FYI on this....

Silicone is a contaminant to Oxygen sensors, it will ruin them in a hurry.

Most typical Oxygen sensors obtain their fresh air samples by drawing through the wiring.

You globbed RTV silicone on your wiring.

If that stuff did not clearly state 'oxygen sensor safe' on the label, there's a good chance your new sensor will fail in the near future.

 
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No kidding. Theres something I didn't know. Well that kinda sucks, but I'll just do it again on a new sensor.
If at first you don't succeed....
I have one more resistor anyway.

 
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Would take about 5 minutes or less to remove it, clean silicone off and replace it.

 
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Two years for aftermarket cat is very good. They don't last.

 
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Use heat gun glue instead.

 
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The part of the sensor that samples air is inside the cat.
Wires are used to pass electrical signals. That is all the wires do.

When I soldered on the components I removed wire insulation. I sealed the connections with RTV and installed heat shrink.
I'm willing to risk an additional $26 to see if the o2 sensor dies on me, or if the p0420 comes back.
If a fresh air sample is being taken, I can't see how it would be accomplished through the wires. The o2 sensor in a 2001 isn't an A/F sensor.

 
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Study sensor theory, operation, and construction.

Taken out of context from the NGK site:
"voltage is generated across the electrodes due to the small difference in oxygen content between exhaust gases and the reference air inside the sensor."

They don't explain where that "reference air" sample comes from or how it gets there.
It's fresh air.
There are gaps between individual strands of wire within the insulation, fresh air is drawn through these in a sort of wicking action.


In the early days, oxygen sensors had a small hole in the side of the sensor body where this reference air was obtained.
Problem with that was that stuff could enter, clog, block, or contaminate the sensor through hole and render the sensor inaccurate or just plain bad.
Dealer guys spraying undercoating during new car prep ruined many of those sensors LOL.

To combat this problem, the design changed to what is in use today, drawing the fresh air sample from inside the PCM, through the wiring. (The PCM air is relatively protected and stable inside, few chances for contamination.)


An AF sensor is constructed much like multiple oxygen sensors in one body.



Ever seen a ECM or PCM leaking oil? Leaking gasoline? It can and does happen when a oil sensor or fuel injector leaks and pushes fluid through the wiring, it's exit will be wherever the wiring opens up or terminates in fresh air. All external connections in the engine compartment are weather tight so it ends up at the end. This is really cool (NOT) when the PCM is up in the dash board and there's gasoline leaking out of it.

 
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I read a few articles that explain in general how an o2 sensor works.

The sensor I enhanced had a wiring harness that was over 12 inches long, probably 16-18in. I installed the components by the connector, away from the sensor.
The exposed wire was cleaned with alcohol and then tinned with solder. Then the tinned component leads were attached.
After the component soldering, I covered all areas where insulation was removed and the components with Dow Corning RTV 3140. http://www.dowcorning.com/applicatio...t.aspx?R=109EN

It was left alone in a environmentally controlled lab and allowed to set for better than 20 hours. It was then covered with a mil spec heat shrink.

If there are contaminants in the RTV, scraping it off isn't an option since it was applied to the stranded wire. It air is being pulled through the stranded wire, its much more likely to enter at the ends of the connections and travel down the strands. The RTV should not have penetrated the tinned wire. The RTV is covering the wire, much like the wire insulation.

Its very likely that any air that is sampled by the sensor through the stranded wire is unaffected by the cured RTV. Also the sensor is operating at 600 degrees.

As I posted initially when the concerns were raised, this is news to me. I do not know anything for certain and time will provide data. But I don't see any reason to remove the sensor and scrape off the RTV. I'm willing to concede that it might damage my sensor and require another replacement. But I don't see how it is going to do any damage beyond the sensor.
Any damage that was done by sealing it with RTV was beyond undoing by the time I made the post 2 days ago.
What would be the point in getting upset or trying to undo what has been done? What would it affect? ---Nothing.

 
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Correct. There wouldn't be any collateral damage, it would be limited to the sensor itself.

Unless the computer freaks out and overfuels, leading to possible cat damage.
Wait a minute.....