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-   -   New LS swap/install questions (https://67-72chevytrucks.com/vboard/showthread.php?t=625318)

First c10 04-18-2014 12:34 AM

Re: New LS swap/install questions
 
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First c10 04-18-2014 12:35 AM

Re: New LS swap/install questions
 
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First c10 04-18-2014 12:37 AM

Re: New LS swap/install questions
 
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BR3W CITY 04-18-2014 01:12 AM

Re: New LS swap/install questions
 
You shouldn't have a bank 3 and bank 4, that means your rear 02's are still on.

The LTFT is pretty high at 30, are you sure there aren't any glaring mechanical leaks in the exhaust or vacuum system. No burned wires on the header etc?

Need to figure out if the lean condition is in the tune, caused by a mechanical leak, or a problem like an injector.

First c10 04-18-2014 02:21 AM

Re: New LS swap/install questions
 
Br3w
I didn't see any exhaust leaks. No burning wires the only vacuum leak I had was the heater control valve line that I had not hooked up so I put a plug in it after I seen the codes. What tells you the rear o2 sensors are on? Also. When I re worked the harness it only had 3 o2's Not 4. What do I look at next?

BR3W CITY 04-18-2014 11:53 AM

Re: New LS swap/install questions
 
Quote:

Originally Posted by First c10 (Post 6634437)
Br3w
I didn't see any exhaust leaks. No burning wires the only vacuum leak I had was the heater control valve line that I had not hooked up so I put a plug in it after I seen the codes. What tells you the rear o2 sensors are on? Also. When I re worked the harness it only had 3 o2's Not 4. What do I look at next?

It should only have 2.

I see "bank 3" and "bank4" . Bank 1 and 2 are FRONT driver and passenger, 3 and 4 correspond to the rear set (post-cat) 02 sensors. If they are still enabled in the tune, then the truck will make some attempt to use the information they provide. Your getting lean codes, but the part that surprises me is that your NOT getting catalyst efficiency codes (which you would with the rear 02). Its hard to tell exactly whats happening there, but for the life of me I don't know why you would have 3 02 sensors on the harness.

I see that your in Cali; is this an emission-legal swap, with cats and such? I just noticed the CATTEMP readings.

With any lead code, its never a bad idea to check; fuel pressure,dirty MAF, leaks on injector, fuel pump voltage. Some of those items are related obviously, but many are easy checks.

First c10 04-18-2014 12:16 PM

Re: New LS swap/install questions
 
Quote:

Originally Posted by BR3W CITY (Post 6634808)
It should only have 2.

I see "bank 3" and "bank4" . Bank 1 and 2 are FRONT driver and passenger, 3 and 4 correspond to the rear set (post-cat) 02 sensors. If they are still enabled in the tune, then the truck will make some attempt to use the information they provide. Your getting lean codes, but the part that surprises me is that your NOT getting catalyst efficiency codes (which you would with the rear 02). Its hard to tell exactly whats happening there, but for the life of me I don't know why you would have 3 02 sensors on the harness.

I see that your in Cali; is this an emission-legal swap, with cats and such? I just noticed the CATTEMP readings.

With any lead code, its never a bad idea to check; fuel pressure,dirty MAF, leaks on injector, fuel pump voltage. Some of those items are related obviously, but many are easy checks.

Is bank 3 and 4 O2B2S1 and O2B2S2?
no emissions they should all be removed. I think I have connected a vacuum line to the valve cover vent so that maybe it. You think?

Why would I have a cat temp reading? I dont have a cat.... I am guessing they should be turned off???

vehicle package came from ohio

BR3W CITY 04-18-2014 01:05 PM

Re: New LS swap/install questions
 
02 bank 2 sensor 1 and bank 2 sensor 2. That Bank2Sensor2 is what I keep calling "4" sorry to confuse you. Its the 4th sensor. The "sensor 2" is the rear set of sensors, which should be off.
BUT
CATEMP is a catalyst temp monitor as far as I know, so why you have a reading there is beyond me. And it still doesn't explain why you had 3 o2 sensors on your harness.

I feel like I'm missing the big picture here.

First c10 04-18-2014 01:10 PM

Re: New LS swap/install questions
 
ok so my 08 gmc 3500 has a duramax but when i replaced the cat back system i seen 1 sensor on each bank and another single after the Particulate filter. so thought that maybe the gas rigs were close since the factory exhaust on a gas rig is 2 into 1...
do i need to send my ecm back ls1swap and have him turn that stuff off?

First c10 04-18-2014 05:17 PM

Re: New LS swap/install questions
 
I have a question since both banks show ltft's at 29.7 could the o2 sensors be incorrect?

First c10 04-18-2014 05:49 PM

Re: New LS swap/install questions
 

This is pretty good info!

First c10 04-18-2014 06:13 PM

Re: New LS swap/install questions
 
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ok so I have another question on my scan tool it gives me the info of
"scan tool reads"
O2B1S1(v) = O2 bank 1 sensor 1 volts .060 volts
O2B2S1(v) = O2 bank 2 sensor 1 volts .835 volts
O2B2S2(v) = O2 bank 2 sensor 2 volts .450 volts

How can this be? if I dont have a "O2 bank 2 sensor 2" ????
this maybe the issue with the lean problem since everything works off the O2....

First c10 04-18-2014 09:43 PM

Re: New LS swap/install questions
 
Ok so I disconnected the MAF and the StFT dropped to between -3.1 to +.8 at idle? What does that mean? Bad MAF sensor? But MAF code popped up.

dayj1 04-18-2014 10:01 PM

Re: New LS swap/install questions
 
Quote:

Originally Posted by First c10 (Post 6635242)
ok so I have another question on my scan tool it gives me the info of
"scan tool reads"
O2B1S1(v) = O2 bank 1 sensor 1 volts .060 volts
O2B2S1(v) = O2 bank 2 sensor 1 volts .835 volts
O2B2S2(v) = O2 bank 2 sensor 2 volts .450 volts

How can this be? if I dont have a "O2 bank 2 sensor 2" ????
this maybe the issue with the lean problem since everything works off the O2....

The Bank 2 sensor 2 is showing .450 which is the value for stoich combustion. I've seen that before even with the rear sensors tuned out. In other words the "tuned out" sensors are read by the scanner as stoich.

What stands out to me is that Bank 1 is extremely lean and Bank 2 is rich. Make sure that you don't have your O2 sensors connectors in your harness swapped from side to side because that's the exact symptom you'd have. It happens to people more than you'd think.

First c10 04-18-2014 10:09 PM

Re: New LS swap/install questions
 
If you look at the 4 wires going to the o2 sensor connector, the wires for
the DRIVERS side, BANK 1, will have a white stripe on the PURPLE wire. The
wiring going to the PASSANGER side, BANK 2, will be solid purple, without a
stripe. Is this correct? I will double check I have it this way. Yes I do have it this way !!!

First c10 04-18-2014 10:20 PM

Re: New LS swap/install questions
 
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This is with no MAF connected. Idle is smooth about 600

First c10 04-18-2014 10:21 PM

Re: New LS swap/install questions
 
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Looks better?

First c10 04-18-2014 10:23 PM

Re: New LS swap/install questions
 
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O2 sensor data

BR3W CITY 04-19-2014 12:40 AM

Re: New LS swap/install questions
 
Quote:

Originally Posted by First c10 (Post 6634908)
ok so my 08 gmc 3500 has a duramax but when i replaced the cat back system i seen 1 sensor on each bank and another single after the Particulate filter. so thought that maybe the gas rigs were close since the factory exhaust on a gas rig is 2 into 1...
do i need to send my ecm back ls1swap and have him turn that stuff off?

I don't know much about the oil-burners, but on any obdII car with a 2-bank engine (so v-anything), you'll have a minimum of 4 oxygen sensors. 2 upstream and 2 downstream. The rear 02's main job is to monitor catalyst function/heat/efficiency...hence why we tune them out. If they are still wired in or left "on" in the tune, there is an issue. When under cold start, or at WOT these sensors are ingored.

First c10 04-19-2014 12:44 AM

Re: New LS swap/install questions
 
Makes sense. I read somewhere on here about someone disconnecting the MAF. When I did the numbers came back inline and the idle mellowed. Bad MAF?

BR3W CITY 04-19-2014 12:07 PM

Re: New LS swap/install questions
 
unplugging the MAF forces it just to use the tables. That usually boils down to bad maf, bad maf wiring, vacuum leak, or something wacky in the tune.

Have you tried driving it at all with the maf unplugged? It should drive, it just may set MAF codes and the trans may feel sticky/harsh. You can clean the maf, reset the ecm (pull battery) and let it cold start idle again. It may re-learn the maf if it was dirty. If its physically broken (element broke etc), this wont' help. I'd pickup one from the parts store, troubleshoot the above issues, then try swapping it out.

First c10 04-19-2014 03:17 PM

Re: New LS swap/install questions
 
Hey br3w
I checked the power at the MAF it is correct not sure about signal wires but the only thing I did was power and ground. I drove the truck and yes runs fine but did throw MAF code and temp code. The MAF was a brand new one but I guess I could get another. I have been all over the manifold trying to find a leak. Even plugging everything coming out of the manifold.
Thanks for all your help.

BR3W CITY 04-19-2014 03:19 PM

Re: New LS swap/install questions
 
Which temp code, the one for the IAT?

I tried to look at your picture and see where the maf was mounted but it was too hard to tell.
How far from the TB is the MAF, is it on a straight section of pipe, and how is it oriented (which way does it face, and what clocking does it sit at)?

dayj1 04-19-2014 09:05 PM

Re: New LS swap/install questions
 
First C10,

Back in post 21, you said you got P0171 and P0172 codes and went on to say that those are for lean AFR on banks 1 and 2. If that's not a typo on the codes, that's incorrect. P0171 is lean bank 1, but P0172 is actually rich on bank 1. So you're getting rich and lean codes on the same bank.

First c10 04-19-2014 10:01 PM

Re: New LS swap/install questions
 
Quote:

Originally Posted by dayj1 (Post 6636755)
First C10,

Back in post 21, you said you got P0171 and P0172 codes and went on to say that those are for lean AFR on banks 1 and 2. If that's not a typo on the codes, that's incorrect. P0171 is lean bank 1, but P0172 is actually rich on bank 1. So you're getting rich and lean codes on the same bank.

Both lean codes sorry. P0174 I think it was.
To many numbers!!!!
I will post a picture of where my MAF is located.


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