Cold weather=Rich tune???

[coryhussey]

Hey all, it has been pretty cold around here lately. Roughly 10-32 degrees farenheit. My truck keeps throwing a DTC, po172 and 175. Bank 1 and 2 are too rich. Is it because of the air is so dense and cold that their is too much fuel. It doesnt make sense in my head. It has been guzzling gas the last few weeks, and am getting tired of it throwing codes, and being sluggish as hell. Any help is appreciated.

cory

[gmh308]

Hey all, it has been pretty cold around here lately. Roughly 10-32 degrees farenheit. My truck keeps throwing a DTC, po172 and 175. Bank 1 and 2 are too rich. Is it because of the air is so dense and cold that their is too much fuel. It doesnt make sense in my head. It has been guzzling gas the last few weeks, and am getting tired of it throwing codes, and being sluggish as hell. Any help is appreciated.

cory

Have you logged the O2's to see what they are doing?

:cheers:

[coryhussey]

no i have not yet. I may do that 2 morow. What is the best way going about logging the 02's. i have V1 edition.

[gmh308]

no i have not yet. I may do that 2 morow. What is the best way going about logging the 02's. i have V1 edition.

Not familiar with V1, and also not aware of which truck/PCM/OS cal you are running, but most likely you will have access to O2 sensor voltage, which at up to temp cruise and in closed loop should oscillate something like a rough sine wave as the mixture is switched back and forth to try and maintain 14.7:1.

You would need to monitor Closed/Open loop status to ensure you are in closed loop. If you are in open loop, then thats a different story.

Have you done any specific tuning in the past?


:cheers:

[coryhussey]

I hvae done some tuning, but it has been more tranny fine tuning than anything. I had the tune done by black bear performance, but have been tweaking my tranny since the torque converter and servo install. I have not done too much logging for the engine per say. I have access to the 02 voltage, and will have to look more into logging some runs to see how rich i really am.

[joecar]

Select these pids:
LONGFT1
LONGFT2
HO2S11 (bank 1, sensor 1)
HO2S21 (bank 2, sensor 1)

and keep the channel count to 24 or less (unselect some other pids);

then go into the V1 BBL programming page and program the pids.

[Chevy366]

Is this a COS Speed Density tune ? , if not , the MAF should handle any temp difference with ease .
Larger cam ? Injectors ? What are the specs of the truck ?
Run fine before then just started since cold weather ?

[coryhussey]

truck has had a tune on it for a year. via black bear. has screenless maf, volant cai, z06 cam and springs, thats it motor wise. new plugs 3 months ago. its an 03 5.3

[Sid447]

truck has had a tune on it for a year. via black bear. has screenless maf, volant cai, z06 cam and springs, thats it motor wise. new plugs 3 months ago. its an 03 5.3

It might be easier if you post up the tune.

[coryhussey]

take a look at this. I did a few logs as suggested by joecar. I saved them but am not sure if i post them up, they will show up, here is the current tune anyways

[Chevy366]

Probably your MAF .

[joecar]

You can post your current logs here.

In later logs, do include these pids:
VSS
RPM
TP
MAF
MAP
IAT
ECT
AFR
SPARKADV
KR
IBPW1
IBPW2
DYNAIR
DYNCYLAIR_DMA
LONGFT1
LONGFT2

Maybe include these:
HO2S11 (not HO2S12 or HO2S22)
HO2S21 (not HO2S12 or HO2S22)

Post your current logs anyway.

[coryhussey]

i logged the ho2s11 and 21. the graph when it is recording live was very rough. it was up and down when idling, but smooth when revving the engine.

i dont know if these will show up.

[dc_justin]

Cory,

Definitely the MAF de-screening causing the issue. As a result, MAF calibration table is inaccurate and needs to be dialed in.

Justin

[coryhussey]

its weird how i have never had any problems with it last winter. just this winter it has started.

[coryhussey]

how much should i adjust the MAF if i do. here are the #'s
1.742188
2.062500
2.421875
2.835938
3.289063
3.789063
4.351563
4.953125
5.609375
6.335938
7.109375
7.960938
9.312500
10.343750
11.437500
12.601563
13.828125
15.171875
16.617188
18.187500
19.851563
21.648438
23.554688
25.570313
27.710938
29.968750
32.328125
34.812500
37.390625
40.085938
42.929688
45.023438
48.156250
51.453125
54.914063
58.539063
62.328125
66.906250
71.046875
75.343750
80.609375
85.296875
90.195313
95.304688
100.609375
106.085938
111.773438
117.640625
123.726563
129.968750
136.421875
143.070313
149.929688
156.984375
164.273438
171.703125
179.390625
187.304688
195.460938
203.859375
212.523438
221.523438
230.867188
240.406250
250.289063
260.476563
270.976563
281.796875
292.851563
304.125000
315.703125
327.617188
339.867188
352.484375
365.484375
378.906250
392.765625
407.085938
421.914063
437.296875
453.265625
469.921875
487.257813
505.328125
511.992188

[joecar]

Clean the MAF sensor and see if there's any difference.

[coryhussey]

i cleaned the maf and got rid of code po175, 172 still comes back here and there. I did a little tuning on the maf, and i think that got rid of the 175 code. I am not sure if i should tweak a little more to try and get rid of the 172 code. Maybe going back to the screen MAF may help with this code as well. I dont know if it would be the oxygen sensors, checked all the vaccum hoses, it may be a injector clogged, but all the pressure seems to be the same all the way across.

[coryhussey]

also this cold weather is killing gas mileage. I have read up on it, and obviously the denser cold air is culprit. The computer is trying to keep the A/F ratio at the optimal 14.7:1, so it is sucking more fuel to compensate. anyway of tuning this out.