Installed OFH but...

[ShibaYuki]

Originally Posted by jvincent

@ShibaYuki, did you put new gaskets in as well?

Yes. Brand new gaskets from the dealer. Torqued to spec. Brand new rear O2 sensor. Re flashed to stock then flash back to stg2 UEL 91 oct.

Update(not so much) 3:
I have been driving around the city for an hour after I reflashed it and I haven't gotten the actual CEL on the car. But I check at the OFT ECU fault codes. The P0171 code is popping up there. This is a dang headache. Lol.

[wparsons]

How many times have you driven it, and did you clear the code before flashing back to stock?

Codes will be stored for a bunch of drive cycles before they disappear, even if the issue that caused them to show up is gone.

[ShibaYuki]

Originally Posted by wparsons

How many times have you driven it, and did you clear the code before flashing back to stock?

Codes will be stored for a bunch of drive cycles before they disappear, even if the issue that caused them to show up is gone.

I have driven twice in between the one hour after I reflashed it. I took a 5-10 minute break, then went on driving again. There was no codes on the OFT before I flashed it back to stock.
Hmm so should I just keep driving? I plan to empty out my tank today and test it out before I fill it up again. Just to see if the problem comes back up. Plus it's a nice weather to cruise right now.
I'm now taking another 5-10 minute break before I go drive around again to see if it comes back. The CEL hasn't come back yet but the code is in the OFT once in a while.

[wparsons]

It'll take about half a dozen drive cycles to clear a stored code, and a really short drives won't really do much since the car barely gets fully up to temp.

If you're really worried, clear the code and see if it comes back again. If it were dangerously lean at part throttle, you'd be in limp mode.

Just an FYI, lean/rich is read by the primary (front) O2 sensor, the secondary (rear) O2 is only to let the ECU know if the cat is working.

I would go for a good 20 minute drive (including a bit on the highway) while logging commanded AFR, actual AFR, throttle, rpm, long term fuel trim and short term fuel trim.

[ShibaYuki]

Originally Posted by wparsons

It'll take about half a dozen drive cycles to clear a stored code, and a really short drives won't really do much since the car barely gets fully up to temp.

If you're really worried, clear the code and see if it comes back again. If it were dangerously lean at part throttle, you'd be in limp mode.

Just an FYI, lean/rich is read by the primary (front) O2 sensor, the secondary (rear) O2 is only to let the ECU know if the cat is working.

I would go for a good 20 minute drive (including a bit on the highway) while logging commanded AFR, actual AFR, throttle, rpm, long term fuel trim and short term fuel trim.

Thanks! I'll do that right now. (Including highway drive) i have been driving for an hour and half now. I don't think the primary O2 sensor is having any problems though. It didn't look like it was cross threaded. What are the normal numbers for the commanded AFR, AFR, throttle, rpm, ltft and stft?

[wparsons]

The rear O2 won't tell the computer anything about AFR, so that's not contributing to the lean code.

There is no "normal" numbers for those values, there's going to be a wide range. What's important is how they relate to each other.

Add load to the list of things to log, then upload the log to datazap.me and post it up for people to look at.

[D_Thissen]

Originally Posted by wparsons

How many times have you driven it, and did you clear the code before flashing back to stock?

Codes will be stored for a bunch of drive cycles before they disappear, even if the issue that caused them to show up is gone.

If he/she disconnected the battery for a few mintues, would that clear it from the memory?

[ShibaYuki]

Originally Posted by wparsons

The rear O2 won't tell the computer anything about AFR, so that's not contributing to the lean code.

There is no "normal" numbers for those values, there's going to be a wide range. What's important is how they relate to each other.

Add load to the list of things to log, then upload the log to datazap.me and post it up for people to look at.

Originally Posted by D_Thissen

If he/she disconnected the battery for a few mintues, would that clear it from the memory?

I saved them. And I'm not at home yet. Still trying to hope that the ecu learns. Just got off a 40 minute drive including a highway run. Didn't get to push the car on the highway since it's literally traffic. Just got to push the car at the ramp(merging lane) at 3rd gear. Then that's it. After that got off the highway and did a lot of street driving. I really hope it's nothing now. Light hasn't come on. Just any time I press the ecu fault codes in the OFT, sometimes it tells me I have a p0171 code and sometimes it says I have no ecu fault codes. Other than that the car seems to run fine for now and it's pulling. I do smell a little bit of gas smell inside the cabin, but I believe that's because I'm catless all through out. It's not as bad as before when the O2 sensor is actually loose.

[ShibaYuki]

Double posting!

I drove to my girlfriend's house and it was a 40 minute drive (all city driving). And I didn't get any CEL but I clicked the ecu fault codes and I got a P2097 (rich bank 01). But I'm not smelling any thing in the cabin anymore. The car behind me can smell gas though(girlfriend confirmed) that's because I'm catless.
So, should I be worried that my primary (front) O2 sensor be damaged since it's giving me codes through the OFT? Or the ecu still hasn't learned that I have fixed the problem?
Or maybe another air leak (but wouldn't that throw a CEL through the car first?)

[ShibaYuki]

Originally Posted by wparsons

The rear O2 won't tell the computer anything about AFR, so that's not contributing to the lean code.

There is no "normal" numbers for those values, there's going to be a wide range. What's important is how they relate to each other.

Add load to the list of things to log, then upload the log to datazap.me and post it up for people to look at.

http://datazap.me/u/shibayuki/city-d...y?log=1&data=0

Hey, this is one of the logs that I have saved. I'm not too sure what to look for that is abnormal. If so let me know please.
This is my drive home from girlfriend's house with some 3rd gear WOT.

[steve99]

Originally Posted by ShibaYuki

Yes. Brand new gaskets from the dealer. Torqued to spec. Brand new rear O2 sensor. Re flashed to stock then flash back to stg2 UEL 91 oct.

Update(not so much) 3:
I have been driving around the city for an hour after I reflashed it and I haven't gotten the actual CEL on the car. But I check at the OFT ECU fault codes. The P0171 code is popping up there. This is a dang headache. Lol.

Unfortunatly the rear 02 is only used for cat efficiency checks and cruise fueling minor adjustments.

if you have an oiled air filter definitly clean the maf sensor

probably clean maf sensor anyway and check for intake air leaks

The front 02 is the primary sensor used for engine fueling measurements.

If p0171 came back you still have a problem if no leaks it likely ptimary front o2 is damaged

All engine ecu codes are cleared on reflash or engine ecu reset, P0171 is an engine ecu code. Other control units may retain codes like body computer vsc computer ect when engine ecu is reset.

If the P0171 came back you still have a problem, did the front o2 sensor unscrew easily and did it look ok ? was it scrwed all the way in ?

[ShibaYuki]

Originally Posted by steve99

Unfortunatly the rear 02 is only used for cat efficiency checks and cruise fueling minor adjustments.

The front 02 is the primary sensor used for engine fueling measurements.

If p0171 came back you still have a problem if no leaks it likely ptimary front o2 is damaged

All engine ecu codes are cleared on reflash or engine ecu reset, P0171 is an engine ecu code. Other control units may retain codes like body computer vsc computer ect when engine ecu is reset.

If the P0171 came back you still have a problem, did the front o2 sensor unscrew easily and did it look ok ? was it scrwed all the way in ?

Oh no. Please tell me that's not the problem. The p0171 is showing on the OFT ECU fault codes. Then I just erase it there. I'm not actually getting the engine light in the car. Just checking if there's like a hidden ECU fault codes. The front o2 sensor is actually snug in there. It's not moving and it's screwed in all the way. Although, the washer for the primary o2 sensor is a little loose, but the actual sensor itself is really in there, wont get unscrewed unless I unscrew it.

[steve99]

Originally Posted by ShibaYuki

Oh no. Please tell me that's not the problem. The p0171 is showing on the OFT ECU fault codes. Then I just erase it there. I'm not actually getting the engine light in the car. Just checking if there's like a hidden ECU fault codes. The front o2 sensor is actually snug in there. It's not moving and it's screwed in all the way. Although, the washer for the primary o2 sensor is a little loose, but the actual sensor itself is really in there, wont get unscrewed unless I unscrew it.

usually if the washer is loose its not in all the way and it may be leaking.

I had to chase the threads on my ofh ( same with many headers as when the bungs are welded in they distort a bit) to get the o2 sensor to screw in properly without forcing and so they go in all the way. Even a small leak right near the sensor will cause issues as the sensor sees fresh air with heaps of oxygen and it thinks car is running lean when its not.

If you have not removed the front 02 sensor I would do so then run a tap/chaser through bung then reinstall sensor its M18 by 1.5 pitch

if the sensor is not screwed in all the way it wont work properly either.

check the threads on front o2 sensor for damage as well.

luckly you can get at the front 02 without uninstalling header

[ShibaYuki]

Originally Posted by steve99

usually if the washer is loose its not in all the way and it may be leaking.

I had to chase the threads on my ofh ( same with many headers as when the bungs are welded in they distort a bit) to get the o2 sensor to screw in properly without forcing and so they go in all the way. Even a small leak right near the sensor will cause issues as the sensor sees fresh air with heaps of oxygen and it thinks car is running lean when its not.

If you have not removed the front 02 sensor I would do so then run a tap/chaser through bung then reinstall sensor its M18 by 1.5 pitch

if the sensor is not screwed in all the way it wont work properly either.

check the threads on front o2 sensor for damage as well.

luckly you can get at the front 02 without uninstalling header

Alright, I'll check the primary o2 sensor on Saturday. I may have to buy the chaser. The sensor looks and feels screwed all the way. I need a wrench to loosen the primary o2 sensor. I just really hope the front o2 sensor is not damage. These sensors are dang expensive. How would I be able to get to the front o2 sensor? Just take off the whole intake?