I have seen the 13111s used in hundreds (really) of F-bodies over the years. I ditch the switching codes and do work in the tables that soundengineer mentioned as well as the closed loop integrator delay tables. I don't see any problems or high rates of failure with the 13111's, but the length of their cable has somehow gotten a bit shorter over the years. It's still long enough, just odd that it would change and maintain the same P/N.

 

Thanks for sharing your wisdom Ed. I see you finally learned how to quote on a forum.

 

Steve, any guidance as to the equivalent tables in EFILive and what direction to massage them? I don't see the same optionality there, but the language may be different.

I've ditched the codes as well, but I have to say that I've had the best luck with a pair of used Corvette rears, compared to extensions and Densos that I tried.

 

I don't have anything in front of me to look at right now, but it seems like they are along the lines of STFT base idle correction and it's multiplier and STFT base delay and it's multiplier table. I don't think I'll ever learn the b-numbers.

 

In EFI
b4109 and b4110 I believe

 

I guess everybody knows the 02 switching is not for fuel corrections, but to store oxygen in the cats, right? I hope so. If you have perfect zero fuel trims, it's not making corrections, but still toggling the air/fuel rich, lean, rich, lean for the cats. If you only change the exhaust and get those codes it is due to lower exhaust and 02 temps. Not tuning errors. What you are doing with the tables mentioned is making it switch quicker (not correct fueling errors quicker) just to make the 02s look right to the ECM/PCM. Not fixing any tuning errors. The only way you are making the 02s switch faster is throwing more fuel at them at a faster rate to make them switch high quicker, and pulling it faster to make them switch low quicker. You are just tricking the test, not really fixing anything.

The guy that scaled his injector offset table and helped his switching simply leaned his car. he had Lucus injectors which always need the offset table scaled down anyway. Should have been done at install.

If you can't pass the ASE L1 test you should not be doing this kind of work.

 

were not talking abot 02 switch points... were talking about the various gains needed to drive the o2 across the switchpoint..
if your car doesnt drive the o2's properly then you dont have proper air fuel at idle...and your trims at idle will go all out of whack..


the point of the switching is to center the fuel around stoich for emissions reasons...
when your o2's wont switch at idle.. it usually only takes a very small change in the amount of fuel needed to drive closed loop operation.. I think the base amount on my ls1 fbody was 128...I only had to up it to 140 to get it to switch nicely and have a nice steady sine wave pattern.
some cars need a lot more to fix the issue

the switching of the 02 sensors has nothing to do with the catalytic converters...
the cats are there strictly for emissions reasons...they dont "store oxygen"

they use a catalyst to break down the gasses caused by combustion to make them less harmful to the environment

a simple example...
http://auto.howstuffworks.com/catalytic-converter.htm

 

I'm afraid you are mistaken. What I mentioned came straight from classes at a GM Training Center. Not some internet message board. Might want to take some classes. Unfortunately independant techs can no longer attend the GM centers, but there are other options. I attended those regularly, the best info available and they included some great printed hand outs. I took the ASE certifications tests, even had the little patches on my unifoms. Only wear tee shirts now. ASE L1 is the advanced drivability and emissions certification. You can pay to take those at many local Jr Colleges You can try the L1 test to see how much you do or do not know about it. From what I read, I think most here would find a lot of suprising information there.

That discription on that website to which you posted a link is very simplistic and not very detailed. Pretty typical for the internet.

Stock vehicles with exhaust only changes will set those switching codes with perfect zero fuel trims. It is sensor temps, not tuning changes needed. I see it all the time, most other professional tuners I talk to have seen this many times. According to one of the GM calibrators I know, as long as 14.7-1 is the target you should not have to change the tables you are talking about.

 

 

Anybody interested in actual training and certification can go to this site:
http://www.ase.com/ and sign up for testing. They usually list when and where testing is being held. Usually at a tech school or jr college. Might want to take the test to see where you are. Might hurt your ego, but would tell you where you need training.

 

Got the same problem for over a year now with the 02 gremlin. I put a 5.3
in my 85 El Camino and because of hood clearance. Rmoved the Vortec
EFI and replaced it with a 04, GTO, LS1 intake and exhaust manifolds.
I am add my wits end and tired of throwing money at it. About ready to run it
off a cliff. I didn't want a racer just a good daily driver.

 

It's simply a matter of the 02 running cooler with modified exhaust. I'm not sure why nobody wants to listen to the engineer from Bosch. Most people in this business know the 02s switch faster at higher temps. When the ECM/PCM does not see them switch as fast as it thinks they should at the temp it has calculated or expects (It assumes the exhaust system is stock, that is what the system was desinged for.) it will set that code. I don't know who 70nova goes to for advice, but if they told him it would run in limp home, or open loop mode, he needs to find another mentor. Who he talks to now is dispensing false information. Either do what the Bosch engineer said to do to get the temps up to factory specs, or shut the codes off. Only result from that will be no 02 switching codes. Won't run one bit different, it just won't care if the 02s are as hot as with the factory system, or not. Some are trying to make it into something it's not.

 

What the factory intended us to do with them is partially immaterial on a modified car.

Here is an example of a car that needs to have them fixed and switching VS. codes being deleted: Speed density cars are very sensitive to heat soak in regards to the IAT. 25 false degrees F of IAT will make a SD car dead lean until the sensor reports closer to correct temp. Lazy O2s mean that when it gets in closed loop, they just just kind of hang around at idle rather than driving the car back to stoich quickly. Adjustment of the tables I mentioned above allow you to very quickly drive the O2 back to switch, which brings the mixture right under control and holds it there. In back to back logs the difference is drastic in how quickly the mixture comes into line.

 

Steve, if you get the fueling right, they will switch before they go into closed loop. They won't hang. If they "hang" above .450 mvs, it's rich, which lowers exhaust temps and contributes to lazy 02s. Those codes don't set because they are lazy at startup.

Your right about IAT, but that is not related to the 02 switching codes.

 

Steve,
I have the same problem as the guy with the 70 Nova. Please take a look at post 192.
I have the 85 El Camino with the 5.3, 04 GTO intake and exhaust
manifolds, cats and 02s for hood and frame rail clearance.
Like I stated not building a racer just decent daily driver that will pass California smog law.
But until I get DTC P0134 and 154 code cleared I can't even make appointment with the Ca referee.
No one in my neck of the woods seems to know what to do.
They see that LS engine and don't want anything to do with it.
It has everything on it necessary for Ca smog but can't resolove the code problem.
It seems to run fine and great power but throws the MIL.
The guy that programmed the ECM, turned out to be a flake and can't be found.
So that is my delimena. I would be glad to send you my ECM for programining if you can help.

Thanks,
Joe

 

My p0133 came back again. I noticed at idle the engine wasnt as smooth so I pluged in the obd. P0133.
It happened a few weeks ago but I had other codes thats said o2 malfunction. So I replaced the o2s and it was fine for few weeks.
Has anyone found out anything else on how to fix this?

 

Wow...I had no idea so many people were having the same problem I am.

I just read all 195 postings on this issue and still don't know what to do. I have Bosch 13111's. I think I'll try and drill the holes in the sensor case first and see if that helps.

There are basically 5 schools of thought here:

1. Fix all exhaust leaks, assuming there are any.
2. Drill holes in the Bosch 13111's to allow more heat in.
3. Switch to Delco Sensors with extensions.
4. Turn off the codes.
5. Tune the engine.

QUESTION: Will turning off the codes help me pass an emissions test in Cali? I failed a smog check yesterday because I had too many emissions?

4 years this post has gone on and still no definite answer...Anyone have the definite solution?

 

My solution was to simulate the narrowbands by wiring in a full time set of widebands, and allowing it to send a narrowband signal out to the PCM

 

S.E. can you explain that a little better for me, I'm not as savvy at the car lingo. What are narrowbands and widebands? And where do I pick some up?

Thanks and sorry for being a moron...

 

Bump.