[savannahz]

Hey,

I just changed out my lpfp as I was dipping below 50 in higher rpms. Everything looks good now except my stft are fairly eratic and above 5 apart. They were this way before and after an adaptation resets.

I've tried reading around but still don't understand if they are within reasonable spec. The idle looks good which means my injectors are alright? But, since they become farther apart at higher rpm it could be o2 sensor?

My afr looks good and the car runs well so maybe I shouldn't be concerned?

Thanks!

just idle: https://datazap.me/u/savannahz/idle-...&data=20-21-22

idle then higher rpm while in neutral: https://datazap.me/u/savannahz/idle-...&data=20-21-22

[marv85]

I see nothing weird about your trims. if you want better advice, log an actual run from low rpm to redline.

Fuel control is closed loop. STFT is the amount of trim the DME is applying to hit the AFR dictated in the AFR tables. variance bank to bank is expected and is due to a lot of variables. Either way, the logs you attached are not telling.

[savannahz]

Originally Posted by marv85

if you want better advice, log an actual run from low rpm to redline.

Here is a pull I did today in third gear from 3k to redline: https://datazap.me/u/savannahz/11-2-...&data=20-21-22

Looking back, maybe it's not as bad as I thought. It's only largely separated in brief moments.

[335e92tx]

Link didnt work - is this the one you wanted?

https://datazap.me/u/savannahz/idle-...ata=3-20-21-22

[savannahz]

Sorry, I had made it private...here you go: https://datazap.me/u/savannahz/11-2-...&data=20-21-22


Thanks!

[9krpmrx8]

Everything looks fine to me.

[NA55]

The STFT at idle does look a little odd.. i checked mine and it looks stable.. the STFT at WOT looks ok..

[9krpmrx8]

Originally Posted by NA55

The STFT at idle does look a little odd.. i checked mine and it looks stable.. the STFT at WOT looks ok..

It only matters at warm idle and anything within 5% + or - from 0 is normal for STFT and LTFT.

[savannahz]

Thanks for all the responses. I feel better about the readings.

How many miles on car? Still on stock injectors?

What do the trims/AFRs do when you let off the gas completely after making a pull?

[savannahz]

Originally Posted by FCobra94

How many miles on car? Still on stock injectors?

What do the trims/AFRs do when you let off the gas completely after making a pull?

The car has 81k miles. The injectors were swapped out while in the teens as the fuel pump and whatnot went out before I had it when it was a lease. They are the older index injectors (same index it originally had in 2007...9?).

Here is a pull I did where I just let off the gas at the top of the run and just kept it in gear. The afr goes and stays at 234.95

https://datazap.me/u/savannahz/third...&data=14-15-20

Thanks

[335e92tx]

Originally Posted by savannahz

The car has 81k miles. The injectors were swapped out while in the teens as the fuel pump and whatnot went out before I had it when it was a lease. They are the older index injectors (same index it originally had in 2007...9?).

Here is a pull I did where I just let off the gas at the top of the run and just kept it in gear. The afr goes and stays at 234.95

https://datazap.me/u/savannahz/third...&data=14-15-20

Thanks

Time to replace o2 sensors. Look how long it takes for lambda to go to 234 after throttle closure..

They are slow.

Originally Posted by 335e92tx

Time to replace o2 sensors. Look how long it takes for lambda to go to 234 after throttle closure..

They are slow.

That's what I was getting at, but my thinking is that this is pointing to leaky injectors...refreshing primary O2s is not a bad idea though.

[savannahz]

Thanks for the great information

I have been getting for the past several months a 2C7F trimming "lambda control 2" code. It's a shadow code and I haven't been able to get anything out of my research short of ignore it as I have catless dp's.

Last time I checked my plugs to see if they were wet they looked good. I'll do another check.

I should probably replace the oxygen sensors due to age anyhow. We are talking about the two closest to the engine (is that upstream)?

Looks like the Bosch 17098 is a reasonable option? Can I use this for both banks, or do I need to use Bosch 17102 for cylinders 4-6?

Is it just the wire length that's the difference?

Yeah, just wire length...go with the cheaper option (17098).

[savannahz]

Originally Posted by FCobra94

Yeah, just wire length...go with the cheaper option (17098).

Awesome, I just ordered a couple and will update the thread once I get these installed with a new log. I have noticed my gas mileage went down by a couple over the past half a year, or so.

Again, you guys are great and I really appreciate the help!

[savannahz]

Originally Posted by 335e92tx

Time to replace o2 sensors. Look how long it takes for lambda to go to 234 after throttle closure..

They are slow.

I replaced both primary O2 sensors and have a new log. I tried to do what you did in the screenshot, but couldn't figure it out...do they still look slow? Are the sftf numbers too far negative at the beginning of the run?

thanks!

https://datazap.me/u/savannahz/log-1...ata=3-22-23-24

excel log screenshots before and after 02 replacement:

View post on imgur.com

Looks good to me.

You can always reset adaptations and try again though.

[335e92tx]

yep, looks like they are to full lambda in .4 sec.. I doubt you can get much quicker. Looks like it took .7 secs before.

[savannahz]

wow, that's awesome. Thanks for taking the time. Makes me feel a lot better.

Thanks to everyone for their help...means a lot.