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02s being weird

gtpsleeper

gtpsleeper

New member
Sooo Im at a loss here. I recently went back to closed loop from being open loop for the longest time and my 02s are acting.... weird.

Basically, it will cycle like normal then it will just be pegged (like in power enrichment) outta nowhere... I have no idea why and there does not seem to be a constant in the happening of it. I changed my 02 and it still does the same thing. If someone can tell me how to put HPTuner stuff on here I can show a scan and my current tune.

Any ideas?
 


What model year is your car? And who tuned it?

What temp is your thermostat? What temps do you see when this is happening?

I just worked on a Buick Regal that was just pissing gas with a drilled 160 degree thermostat in Colorado winter weather.
 
Shmoke said:
What model year is your car? And who tuned it?

What temp is your thermostat? What temps do you see when this is happening?

I just worked on a Buick Regal that was just pissing gas with a drilled 160 degree thermostat in Colorado winter weather.
Click to expand...

2002 gtp, me, 160(non-drilled), and engine temps stay constantly around ~170 to~180 but I see it happening when closed loop is enabled.

Explicit_Spade said:
Is your o2 sensor good? Do you have a wideband?
Click to expand...

My original one was less than a year old but then I changed it out with the current one a few days ago with the exact same results. Yes, I have a wideband. When the narrowband is cycling like normal, the WB is reading consistently ~.93 to ~1.1 lambda. When the WB "pegs" and stops cycling (say around 930 mv) its goes anywere from .7-.8 lambda (again, like its trying to go into PE mode). The best way I can describe it is that it is going into PE mode randomly for no reason. Even my LTFTs are barely off when this happens...
 
Have you disabled your Catalytic Converter performance tests by using TinyTuner v3 to set "Diagnostics>Main>CAT Diagnostic Tests Count to Pass" to 0 (zero)? Also set "CAT Diagnostic Tests per Trip" to 1?
 


91parkave said:
So you just went back to closed loop? Never changed your fueling any? Still running e85?
Click to expand...

Yes, Yes and Yes... main reason I did it was to dial it in even closer as the fuel changes from true e85 to ~e79 from Dec. to Jan. and then is constantly true e85 all other times of the year (at the station I go to anyway).

Shmoke- I have never used tiny tuner so Im going to say no... But, I have never had this issue in the past either so if it were the cat diagnostics I dont know why it would choose now to start being temperamental.
 
gtpsleeper said:
Yes, Yes and Yes... main reason I did it was to dial it in even closer as the fuel changes from true e85 to ~e79 from Dec. to Jan. and then is constantly true e85 all other times of the year (at the station I go to anyway).

Shmoke- I have never used tiny tuner so Im going to say no... But, I have never had this issue in the past either so if it were the cat diagnostics I dont know why it would choose now to start being temperamental.
Click to expand...

Gotcha..did you ever change your stoich value in your tune?
 
Yes, I did once on the initial switch. But again, I haven messed with ANY of that since then. Only thing I have messed with in the entire tune since the switch was the initial Injector change and the maf twice a year (for the changes in ethanol) and thats it. No parts are new other than some routine sensors and such.

Searching around hasn done much good due to the uniqueness and "O2" being too short for the search to do doesn help either.

appreciate all the interest so far and honestly if I cant figure this out Im gonna switch back to the open loop and say screw it. It wasn far off anyway Im just kinda OCD when it comes down to it.
 


The best way I know to host a HPT scan is to get on HPT's forum, make a thread, and then just post the link over here.
 


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