Thread: 02s being weird

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.

Is your o2 sensor good? Do you have a wideband?

Originally Posted by Shmoke

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.

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.

Originally Posted by Explicit_Spade

Is your o2 sensor good? Do you have a wideband?

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...

So you just went back to closed loop? Never changed your fueling any? Still running e85?

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?

Originally Posted by 91parkave

So you just went back to closed loop? Never changed your fueling any? Still running e85?

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.

Originally Posted by gtpsleeper

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.

Gotcha..did you ever change your stoich value in your tune?

Arent you running a 2000 L67 PCM in that instead of the stock 2002 PCM?

Though that shouldn't change much.

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.

Originally Posted by Fivefingerdeathpunch

Arent you running a 2000 L67 PCM in that instead of the stock 2002 PCM?

Though that shouldn't change much.

yes, iirc it was from an ssei... (why the sticky about the O2 never affected me)...

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.

just use google docs to host your file free, fast, and easily accesible

https://drive.google.com/file/d/0B1o...it?usp=sharing

Thanks 91... that was easy.

Originally Posted by gtpsleeper

https://drive.google.com/file/d/0B1o...it?usp=sharing

Thanks 91... that was easy.

NP don't forget to set the permissions to share with people

fixed sorry didn notice that

btw... disregard my WB O2 readings as I was not logging them for this

bump... anyone?