Paul, you might PM Joecar on any wiring concerns or specific test to insure those O2's are functioning properly. Some headers (ceramic-coated vs non-ceramic coated) effect the EGT and the resulting O2 functioning. There is also wiring into the harness/PCM that is way over my head.
I do know we need them switching properly to continue with closed-loop..
Long tube headers:
steel loses more heat than stainless;
no ceramic coating loses more heat than ceramic coated.
The NBO2's require to be kept heated up from the exhaust gas heat.
Joecar,Originally Posted by joecar
I have uncoated 304SS longtube headers. The front NBO2's are heated. Is there any type of test that i could perform that you may know of or a certain type of NBO2's to use? I just replaced the front factory ones with 2002 Corvette secondary in the primary position. I have no problem getting what i need for testing or modifying. I am just as curious to what is going on.
On my ride home tonight it is running lean, I didn't scan just watched the WBO2's. When come to a stop at traffic light it is running 20-25 to 1 at idle very lean.
I really appreciate what you and Shawn are doing to help me on this crazy truck.
Paul
Is there any airleak at the collector...?
Not that I know of, I will put on lift and check.
Paul
I have seen a similar problem like this. the problem in our case was that the NB Front 02 sensor connectors were switched from the correct side. IE: The drivers side harness was plugged into the passengers side 02 and vise versa. This gave us the same issues you are dealing with. We swithced them and presto, everything was great. Hope this helps.
Paul, any update on your vehicle?
Shawn, yes here is my latest tune and scan from yesterday. I have finally got the truck running without any O2 errors so far.
I tuned the MAF in OL with no LTFT and then turned on CL and have the following results.
I also setup a map to track WB at each hz Freq of the MAF to track it as well as a map to track MAF g/s at each Freq. and then calculate changes needed to MAF this worked great in OL. I have the Commanded AFR and the WB's with in 2% of each other, then turned on CL and all hell breaks loose.
I did notice that I ran out of MAF and the truck runs much better in OL (but ran out of MAF) than CL, I need some help with CL in that MAF is demanding 507g/s at 10625hz this was only a very short 64mph burst in the log, when i ran it before it was displaying 589g/s at 11000hz 80mph run up. I have done a little mod to my VE.
My question is this:
If the truck is displaying 9.5afr on WB in higher freq. and i look at my calc-ve log and it is asking for more VE (159 - 178%) in higher rpm, how do i get the truck to run proper AFR at part throttle? not 9.5 to 1? Truck is very sluggish in CL, very crisp and responsive in OL.
Any suggestions?
Paul
Some of what you saying does not make total sense. If your AFR's in OLMAF were good, then going back to CL would have zero effect in PE Mode. So there should have been no change in AFR at WOT.
What I am seeing is that you are incredibly rich in your entire Tune. It is throwing off your CALC VE Table to a great degree.
Have you thought of doing the CALC.VET instead..http://forum.efilive.com/showthread....tire-VE-Table.
Even if you go back to OLMAF you will incredibly rich at WOT..Not sure what happened, but it has nothing to do with closed-loop at WOT..
Shawn,Some of what you saying does not make total sense. If your AFR's in OLMAF were good, then going back to CL would have zero effect in PE Mode. So there should have been no change in AFR at WOT.
What I am seeing is that you are incredibly rich in your entire Tune. It is throwing off your CALC VE Table to a great degree.
Have you thought of doing the CALC.VET instead..http://forum.efilive.com/showthread....tire-VE-Table.
Even if you go back to OLMAF you will incredibly rich at WOT..Not sure what happened, but it has nothing to do with closed-loop at WOT..
I agree with you analysis that is why i was baffeled. ?I am going to do a calc.vet and let you know.
PAul
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