P0171 & P0174..what causes it??
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From: O'Fallon-MO.
P0171 & P0174..what causes it?? It says Fuel trim lean bank 1 and the other code is for bank 2.
I had never gotton this code until I put my LS6 intake on.I'll clear it and it will pop on soon as i start the car.I can't see me pulling this code from the intake.I do have a 98' and never read about people pulling this code from putting a LS6 intake on.Did I do something wrong?
My modes are:
-LS6 intake
-Direct flo lid
-3.73 gears
-Vig. 3200
-MAC headers
-Custom x-pipe
Thanks
Mark
I had never gotton this code until I put my LS6 intake on.I'll clear it and it will pop on soon as i start the car.I can't see me pulling this code from the intake.I do have a 98' and never read about people pulling this code from putting a LS6 intake on.Did I do something wrong?
My modes are:
-LS6 intake
-Direct flo lid
-3.73 gears
-Vig. 3200
-MAC headers
-Custom x-pipe
Thanks
Mark
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From: Las Vegas, NV
Re: P0171 & P0174..what causes it?? It means that your LTFTs are beyond the +25 threshold. You need either a MAFT, LS1 Edit, or remove one of your breathing mods. It sounds like the LS6 intake has put you over the top.
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From: Las Vegas, NV
Re: P0171 & P0174..what causes it?? Let me be a little clearer: the combination of LS6 intake, headers, lid, and catback has leaned you out beyond the computer's ability to compensate. Everything I said above applies. Easily corrected, and good news in the sense that your engine is breathing so much better.
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From: Lexington Park, MD
Re: P0171 & P0174..what causes it?? Did you properly torque the intake bolts with a TQ wrench? I've heard overtightening these intake bolts will actually create vaccum leaks which would cause a serious lean condition which you are getting.
Adding an LS6 intake and Lid would not cause this, air entering the motor past the MAF would however. The engine is taking in more air than the MAF is accounting for. There is something else wrong. Do you have a ported or aftermarket MAF installed by any chance? Any leaks between the MAF and TB? All hoses properly connected? I'm still betting on a leak around the intake somewhere.
<small>[ September 03, 2002, 04:49 PM: Message edited by: 98blackSS ]</small>
Adding an LS6 intake and Lid would not cause this, air entering the motor past the MAF would however. The engine is taking in more air than the MAF is accounting for. There is something else wrong. Do you have a ported or aftermarket MAF installed by any chance? Any leaks between the MAF and TB? All hoses properly connected? I'm still betting on a leak around the intake somewhere.
<small>[ September 03, 2002, 04:49 PM: Message edited by: 98blackSS ]</small>
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Re: P0171 & P0174..what causes it?? It could be a vacuum leak I suppose, but when I was getting those codes I just richened up my base on a MAFT (at the time) and the problem was solved. I also foolishly had a ported and descreened MAF, too. Otherwise, similar mods, same codes.
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From: O'Fallon-MO.
Re: P0171 & P0174..what causes it?? I had a ported MAF on.But I put my stock MAF and got the same codes.I took the intake off twice now to check everything and all looks good and bolts are tighten the right way.I guess i could try a MAFT.I do not hear leaks,but I guess i could get a can of that carb spray and spray around the intake for leaks right?
Also I hear a funny sucking noise from the filter area,and while its doing it the idle surges bad.And setting off high idle code sometimes.It wants to idle at 1500rpms!!And I got the idle screw out!!
Last week when i took the intake off I forgot to hook the vacum line off the valve cover when i put it together.And set the lean bank 1 & 2 codes but it would barly idle then and was popping bad when i let off the gas and it stumbled bad when i took off from a stop.Hook it back up and all was good.I had it at the track all day and no codes set,then all the sudden on my last run it set the lean bank 1 & 2 codes while it was just idling in the lanes.
Thanks guys.Anyone else have any ideas?
I guess i'll check for leaks again first,then try a MAFT.
------------------------------------------------
I would like to add that 3 of my friends here locally got 2002 Z28's with actually the same mods I do,mod for mod they are the same.And all 3 of them run in the very low 12's.And the 02' have the LS6 intake already and they have never set that code,thats why i ruled out thinking i would need a MAFT.I'm thinking i got to have some kinda leak somewhere.
<small>[ September 03, 2002, 08:49 PM: Message edited by: slick98ta ]</small>
Also I hear a funny sucking noise from the filter area,and while its doing it the idle surges bad.And setting off high idle code sometimes.It wants to idle at 1500rpms!!And I got the idle screw out!!
Last week when i took the intake off I forgot to hook the vacum line off the valve cover when i put it together.And set the lean bank 1 & 2 codes but it would barly idle then and was popping bad when i let off the gas and it stumbled bad when i took off from a stop.Hook it back up and all was good.I had it at the track all day and no codes set,then all the sudden on my last run it set the lean bank 1 & 2 codes while it was just idling in the lanes.
Thanks guys.Anyone else have any ideas?
I guess i'll check for leaks again first,then try a MAFT.
------------------------------------------------
I would like to add that 3 of my friends here locally got 2002 Z28's with actually the same mods I do,mod for mod they are the same.And all 3 of them run in the very low 12's.And the 02' have the LS6 intake already and they have never set that code,thats why i ruled out thinking i would need a MAFT.I'm thinking i got to have some kinda leak somewhere.
<small>[ September 03, 2002, 08:49 PM: Message edited by: slick98ta ]</small>
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From: Lexington Park, MD
Re: P0171 & P0174..what causes it?? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by slick98ta:
<strong>
Also I hear a funny sucking noise from the filter area,and while its doing it the idle surges bad.And setting off high idle code sometimes.It wants to idle at 1500rpms!!And I got the idle screw out!!
Last week when i took the intake off I forgot to hook the vacum line off the valve cover when i put it together.And set the lean bank 1 & 2 codes but it would barly idle then and was popping bad when i let off the gas and it stumbled bad when i took off from a stop.Hook it back up and all was good.I had it at the track all day and no codes set,then all the sudden on my last run it set the lean bank 1 & 2 codes while it was just idling in the lanes.
Thanks guys.Anyone else have any ideas?
I guess i'll check for leaks again first,then try a MAFT.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">So you still have that funny idle problem and sucking noise every once in a while? That's definitely a concern. Do you have the LS6 intake with the EGR provision or the one without (and blankoff plate on the macs)? I think we're getting somewhere here...
<strong>
Also I hear a funny sucking noise from the filter area,and while its doing it the idle surges bad.And setting off high idle code sometimes.It wants to idle at 1500rpms!!And I got the idle screw out!!
Last week when i took the intake off I forgot to hook the vacum line off the valve cover when i put it together.And set the lean bank 1 & 2 codes but it would barly idle then and was popping bad when i let off the gas and it stumbled bad when i took off from a stop.Hook it back up and all was good.I had it at the track all day and no codes set,then all the sudden on my last run it set the lean bank 1 & 2 codes while it was just idling in the lanes.
Thanks guys.Anyone else have any ideas?
I guess i'll check for leaks again first,then try a MAFT.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">So you still have that funny idle problem and sucking noise every once in a while? That's definitely a concern. Do you have the LS6 intake with the EGR provision or the one without (and blankoff plate on the macs)? I think we're getting somewhere here...
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From: Lexington Park, MD
Re: P0171 & P0174..what causes it?? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wrencher:
<strong>Sounds like a vacuum leak to me if it sets lean codes at idle, idles high I would start to look for were it is leaking.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm almost positive that's what it is. That's why I asked about the EGR. Pretty common source of leaks if the rubber O-ring is not sealing properly. Just want to eliminate that area first if he no longer has an EGR...
<strong>Sounds like a vacuum leak to me if it sets lean codes at idle, idles high I would start to look for were it is leaking.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm almost positive that's what it is. That's why I asked about the EGR. Pretty common source of leaks if the rubber O-ring is not sealing properly. Just want to eliminate that area first if he no longer has an EGR...
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From: O'Fallon-MO.
Re: P0171 & P0174..what causes it?? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 98blackSS:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wrencher:
<strong>Sounds like a vacuum leak to me if it sets lean codes at idle, idles high I would start to look for were it is leaking.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm almost positive that's what it is. That's why I asked about the EGR. Pretty common source of leaks if the rubber O-ring is not sealing properly. Just want to eliminate that area first if he no longer has an EGR...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have the LS6 intake without EGR.And I have block-off plates for the Headers.That was one reason I took the EGR off was because of a leaky O-ring.
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wrencher:
<strong>Sounds like a vacuum leak to me if it sets lean codes at idle, idles high I would start to look for were it is leaking.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm almost positive that's what it is. That's why I asked about the EGR. Pretty common source of leaks if the rubber O-ring is not sealing properly. Just want to eliminate that area first if he no longer has an EGR...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have the LS6 intake without EGR.And I have block-off plates for the Headers.That was one reason I took the EGR off was because of a leaky O-ring.
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Re: P0171 & P0174..what causes it?? As I think about it, where I'm at now with basically the same mods as you, and a stock maf, is MAF table x 107% and PE vs RPM x 107%. So I don't think I would throw those lean codes even if I zeroed those tables out. I stand corrected, there is something not right. I remember now that I did have an egr leak, too, when I had those codes. Have you scanned your car since getting those codes? That should indicate what's wrong. Good luck!
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From: Lexington Park, MD
Re: P0171 & P0174..what causes it?? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by slick98ta:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 98blackSS:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wrencher:
<strong>Sounds like a vacuum leak to me if it sets lean codes at idle, idles high I would start to look for were it is leaking.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm almost positive that's what it is. That's why I asked about the EGR. Pretty common source of leaks if the rubber O-ring is not sealing properly. Just want to eliminate that area first if he no longer has an EGR...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have the LS6 intake without EGR.And I have block-off plates for the Headers.That was one reason I took the EGR off was because of a leaky O-ring.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Ok, then that's ruled out. Everything tight around the TB? Searching for leaks can be a pain in the butt.. And you're positive the intake was tightened to 44 in-lbs, then 89 in-lbs? Not ft-lbs right? Hey, I've seen someone attempt it. hehe.. Good luck. That carb spray may help in troubleshooting.
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 98blackSS:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wrencher:
<strong>Sounds like a vacuum leak to me if it sets lean codes at idle, idles high I would start to look for were it is leaking.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm almost positive that's what it is. That's why I asked about the EGR. Pretty common source of leaks if the rubber O-ring is not sealing properly. Just want to eliminate that area first if he no longer has an EGR...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have the LS6 intake without EGR.And I have block-off plates for the Headers.That was one reason I took the EGR off was because of a leaky O-ring.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Ok, then that's ruled out. Everything tight around the TB? Searching for leaks can be a pain in the butt.. And you're positive the intake was tightened to 44 in-lbs, then 89 in-lbs? Not ft-lbs right? Hey, I've seen someone attempt it. hehe.. Good luck. That carb spray may help in troubleshooting.
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From: O'Fallon-MO.
Re: P0171 & P0174..what causes it?? Well, it might take me a few days to look for the leaks.But i'm going to try some carb cleaner and A-tap it,then get back here.Its not a daily driver so its just sitting in the garage unharmed <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Thanks again guys for helping me
Mark
Thanks again guys for helping me
Mark
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From: O'Fallon-MO.
Re: P0171 & P0174..what causes it?? **Just an update**
I think I may have found the problem.After about 2 weeks of tring everything I could think of, I narrowed it down to my Throttle body.I had it ported and never had a problem then it seemed like when I put the LS6 intake on all my problems started.Well,either the TB was messed up the whole time or that in combination with the LS6 intake caused it,i don't know.But I put a stock TB on today and it's idleing fine with no surging(which i was also was getting)and no more SES light for those 2 codes.So i'm going to put a few miles on it to make sure,but i think i fixed it.
What made me look at the TB was,I took everything except the TB off.That meant the Lid and MAF was off the car and the car was still ideling at 1500+ rpm's.So then I covered the TB blade hole and all the other holes that is in there,I believe they are a vent and one for the IAC motor.And the car was still idleing good.And I figured with all the holes covered it would kill the car from not getting enough air to run.But when I put my hand over the whole TB it would kill the car.So i'm thinking it was leaking around the blade bad!
Sorry for the long story but just trying to explain what i think was the cause.So in other words...Don't mess with the blade!!!or porting around the blade!! I didn't port it so i'm not for what went wrong.
Later
MArk
I think I may have found the problem.After about 2 weeks of tring everything I could think of, I narrowed it down to my Throttle body.I had it ported and never had a problem then it seemed like when I put the LS6 intake on all my problems started.Well,either the TB was messed up the whole time or that in combination with the LS6 intake caused it,i don't know.But I put a stock TB on today and it's idleing fine with no surging(which i was also was getting)and no more SES light for those 2 codes.So i'm going to put a few miles on it to make sure,but i think i fixed it.
What made me look at the TB was,I took everything except the TB off.That meant the Lid and MAF was off the car and the car was still ideling at 1500+ rpm's.So then I covered the TB blade hole and all the other holes that is in there,I believe they are a vent and one for the IAC motor.And the car was still idleing good.And I figured with all the holes covered it would kill the car from not getting enough air to run.But when I put my hand over the whole TB it would kill the car.So i'm thinking it was leaking around the blade bad!
Sorry for the long story but just trying to explain what i think was the cause.So in other words...Don't mess with the blade!!!or porting around the blade!! I didn't port it so i'm not for what went wrong.
Later
MArk
