I guess the plot thickens. I wish it was my hair instead!

My next thought was Six Volvo's post about the gas cap! He didn't say what kind of code he was getting back then.

Is there a code, for the pressure sensor of the emission circuit? I.e. gas tank sensor. If not, then maybe they doubled up on the one code and it is an inside dealer secret. Found by their mechanics on customer service nickels.
The new Computer Diagnostic FEE. Might as well been TAX! Has same number of letters.

I once knew an associate at work who one day decided to get a newer (Mazda) car. It was having a light issue so he took the car in for a service interval that it was due.

So, for the lack of any better excuse, he traded. Meanwhile, he had to drive his same car until he got the new one detailed, licensing and alike for a day or so because the closest Mazda dealer was in the next state. No light the car ran just like it always had!

The story goes, that among his paperwork for the getting the new car was the service work copy and its details. The bill had a gas cap charge on it!

He laughed and said he traded his car because of a bad gas cap. True story!

I told him that he had caught the “new car fever”. He should do what I do “take two aspirins and go to bed” until it passes.

It’s this kind of thinking that helps creates my thin spots about newer cars and service work!

That $400 bill you had, that doesn’t surprise me!

Now losing both sensors has to have something in common. Is that two individual codes or one for both? Common grounds are very possible!

Was the catalytic converter replaced with original or grafted on by a muffler shop? Does it have or did it have a 0-2 sensor in it? Could it have been left out or wires ripped out? You know, like dangling or bunched up in the body somewhere?

A flow problem may cause uneven heating but I don’t want to bite any of this. The car runs good, you say, so flow would not seem to be impaired. I’m curious how come you had to change the converter though? Not, that I’m a history buff…but?

Having no 0-2 sensor voltage makes the ECU think it is running lean. It should in turn make the car run richer but within the default map program. How about your mileage? How about the converter? How is the smell these days?

These computer codes are what I call a “Shot Gun Blast” at a wall. There are several pellets hitting it in a direction to "look only".

They don’t show any detail or things that are really specific.
You have to sort for functions that create the symptom and think what matches to that "related code".

Too much air or not enough fuel could be affecting the sensors but an absolute no voltage code would be nicer. Then you know their out to lunch.
Then all you got to do is find the name of a street leading from that restaurant, while you are on the other side of town of course.

The answers to this dilemma are in “several good manuals” and a willingness to become a greasy page turning, twice thinking detective!

Some Brick Board puzzle persons out there would help too!

Phil