Fuel Trim System Lean, Banks 1 & 2

[Patrick]

I know this has come up before, but I need to get some additional information on what has been discussed in previous threads, when this subject has come up.

Driving home from work late one night in the Z06 after a night meeting, my Check Engine light came on. This, of course, alarmed me: I'd never had any lights come on before. The light was steady, rather than flashing, which calmed a bit.

So after doing a bit of digging through the CAC's archives, I discovered how to pull codes, and then went in search of what the codes meant. This is what I got:

P0171 Fuel Trim System Lean, Bank 1
P0174 Fuel Trim System Lean, Bank 2

(I also found a history code: B0361 Left Actuator Feedback Short to Ground. As it's a history code, I've discounted it, and since cleared it.)

At first, when I got this code, I assumed it meant the car was reacting to the gas I got at my last fill up. (I did, after all, use a different brand.) I cleared the codes, the Check Engine light went off, and I thought nothing about it. Until it happened again today, a little over a week after the first incidence, after I filled up with the brand of gas I normally use.

Does this mean it's not the gas at all, but something else? If so, what else could it be? Any ideas?

Thanks!


-Patrick

 

[KOPBET]

Dirty halogen fluid . . .

 

[Mr.Cool]

Is your air duct connected tightly to your Maf?
Do you use one of those aftermarket filters that you have to oil? If so maybe your Maf sensor is dirty.
How about your electrical connections to the maf and iat. Are they tight and no corrosion?

 

[LLC5]

Contaminated fuel injectors can set these codes. I would try a bottle or two of Techron "Concentrate" in 20oz. size, following the instructions on the bottle. Techron comes in many flavors, you want the 20 oz. concentrate bottle. Try to only use Top Tier fuel if you can. A Google search of Top Tier Fuel, or toptierfuel.com should work to find the participating stations.

 

[Patrick]

Dirty halogen fluid . . .

Yes, Thank you, Kopbet. I was hoping for someting a bit less apochryphal.

The thing about the MAF sensor, or other factors, that causes me some pause is that I've done nothing in the last several months, I've done nothing which would have resulted in how the MAF sensor is connected. Indeed, I can't find anything wrong with connection right now.

As far as the air duct being connected tightly to the MAF, same thing- I've done nothing under the hood since before the trip to Bowling Green in June.

Perhaps I'll schedule an appointment with the Service Manager regarding the fuel injector. The Z06 still has a few months of warranty left on her, so this may be a good investment of time and effort.

Thanks for the advice, folks. I'll let you know what I find out.

-Patrick

 

[Bioscache2]

Yes, Thank you, Kopbet. I was hoping for someting a bit less apochryphal.

The thing about the MAF sensor, or other factors, that causes me some pause is that I've done nothing in the last several months, I've done nothing which would have resulted in how the MAF sensor is connected. Indeed, I can't find anything wrong with connection right now.

As far as the air duct being connected tightly to the MAF, same thing- I've done nothing under the hood since before the trip to Bowling Green in June.

Perhaps I'll schedule an appointment with the Service Manager regarding the fuel injector. The Z06 still has a few months of warranty left on her, so this may be a good investment of time and effort.

Thanks for the advice, folks. I'll let you know what I find out.

-Patrick

Patrick I had this same problem and our resident tech (c4c5) told me to look for a hole or gap in the intake duct, especially after the MAF. I found this, closed the gap, and hadn't have a problem since. Here is the original post.

 

[Mr. Lucky]

Patrick I had this same problem and our resident tech (c4c5) told me to look for a hole or gap in the intake duct, especially after the MAF. I found this, closed the gap, and hadn't have a problem since.

I tend to agree with this theory... especially since both bank 1 and bank 2 (left & right side) are set. I think it is more likely caused by a common denominator, rather than multiple injectors (though Techron can't hurt).

FYI, here is the troubleshooting info for those codes:
P0171
P0174

 

[MsSchroder]

Do you still have a custom program for the Z? Do you think that might be related in any way?

Tammy

 

[Patrick]

Tammy,
Whatever programming my Z06 had (put in by the previous owner) was over-written last summer when I took it in to have the Column Lock Recall work done. I can't see how that could be the issue here.

The check engine light came again on the way home from work tonight- this time, it's just the P0171 Code that came not, not both.

This is really beginning to bother me. Some in depth investigation is in order. Stay tuned...


-Patrick

 

[Patrick]

And the verdict is a faulty fuel pump. Had it replaced under warranty. So far (only a few hours since I got it back), no issues.


-Patrick

 

[KOPBET]

An apocryphal tale I'm sure.

Better check that halogen ... :W

 

[Patrick]

Kopbet, "Apocryphal"?

Res ipsa loquitur.


-Patrick

 

[KOPBET]

Kopbet, "Apocryphal"?

Res ipsa loquitur.


-Patrick

Ex nihilo nihil fit,

 

[Bioscache2]

alright you two. Knock it off and play nice with the rest of the kids and speak english.

 

[Patrick]

But Ryan, as Kopbet put it so succintly, that little exchange was all about "nihilo." :L

-Patrick