System Lean P0171
Thread Starter
Racer
Joined: Feb 2013
Posts: 254
Likes: 5
From: West coast Canada
System Lean P0171
Getting this code,
Car is running like crap, rough idle, can feel surging throughout rpm
Going out to spray some brake clean around try and find a vacuum leak, no Maf codes, no 02 codes, just 171
Trying to figure this out before I dice roll and take it into the dealer with the stock tune and long tubes with off road x installed...
Any other tips corvette forum suggests it may be?
Car is running like crap, rough idle, can feel surging throughout rpm
Going out to spray some brake clean around try and find a vacuum leak, no Maf codes, no 02 codes, just 171
Trying to figure this out before I dice roll and take it into the dealer with the stock tune and long tubes with off road x installed...
Any other tips corvette forum suggests it may be?
Safety Car
Joined: Nov 2007
Posts: 4,144
Likes: 391
Did you say, "long tube headers" are these installed? Sounds like you have a bad tune or need a tune for your mods!
headers usually cause a lean condition due to more air flow in the exhaust system.
also a leak at the header flange to head will allow more air into the system. The O2 sensors will pick this up, and set the code.
headers usually cause a lean condition due to more air flow in the exhaust system.
also a leak at the header flange to head will allow more air into the system. The O2 sensors will pick this up, and set the code.
Last edited by Racer86; Sep 15, 2015 at 03:03 PM.
Team Owner
Joined: Jan 2007
Posts: 29,063
Likes: 1,839
From: cookeville tennessee
Did you say, "long tube headers" are these installed? Sounds like you have a bad tune or need a tune for your mods!
headers usually cause a lean condition due to more air flow in the exhaust system.
also a leak at the header flange to head will allow more air into the system. The O2 sensors will pick this up, and set the code.
headers usually cause a lean condition due to more air flow in the exhaust system.
also a leak at the header flange to head will allow more air into the system. The O2 sensors will pick this up, and set the code.
If this was the case it would also be makes a bad exhaust leak sound also correct. I don't see it being this. But a rubber hose are something on one of the fittings yes that sucks air....To the OP here if you have put the back 02 sensors in the front it will do this please if you JUST put the headers on the car & one of the 02 senors got HIT just a little that will damage the 02 sensor..
SO did the car run good before the headers & you JUST put the headers on the car & now it is running like crap & doing the code.
Thread Starter
Racer
Joined: Feb 2013
Posts: 254
Likes: 5
From: West coast Canada
Car has had headers for 10k miles now, problem tune is gone, running good tune now, and havent had any issues the past month
Cleaned the maf, went over all bolts, and lines, lean code is now gone, however one for a bank 1 sen 1 o2 low voltage has now popped up, which is a new o2; got replaced during header install because stock ones threads were fused to the bung, the extension wire has had some melting from the past on the one connector, but no issues the past 10k miles, just ordered a new extension anyway to replace that, and go from there i guess
Cleaned the maf, went over all bolts, and lines, lean code is now gone, however one for a bank 1 sen 1 o2 low voltage has now popped up, which is a new o2; got replaced during header install because stock ones threads were fused to the bung, the extension wire has had some melting from the past on the one connector, but no issues the past 10k miles, just ordered a new extension anyway to replace that, and go from there i guess
Team Owner
Joined: Jan 2007
Posts: 29,063
Likes: 1,839
From: cookeville tennessee
Car has had headers for 10k miles now, problem tune is gone, running good tune now, and havent had any issues the past month
Cleaned the maf, went over all bolts, and lines, lean code is now gone, however one for a bank 1 sen 1 o2 low voltage has now popped up, which is a new o2; got replaced during header install because stock ones threads were fused to the bung, the extension wire has had some melting from the past on the one connector, but no issues the past 10k miles, just ordered a new extension anyway to replace that, and go from there i guess
Cleaned the maf, went over all bolts, and lines, lean code is now gone, however one for a bank 1 sen 1 o2 low voltage has now popped up, which is a new o2; got replaced during header install because stock ones threads were fused to the bung, the extension wire has had some melting from the past on the one connector, but no issues the past 10k miles, just ordered a new extension anyway to replace that, and go from there i guess
say that will be it..
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
Your major issue are your LT headers LT's move the front 02 bungs as much as 3' further AFT than the stock exhaust manifolds---This will make your front 02's always read incorrectly and not heat up properly----This is why they are not legal in many states
LT's will eat up front 02's--In the LS days there were some fixes like installing the rear 02's onto the front locations as the rears are more sensitive---however there is no 100% fix----Also you can alter the 02 switching points to try to compensate for the erroneous 02 readings---The front 02's only control your P/T fueling--unless you have a lean condition where the EM is adding fuel to compensate---Whenever you have a lean condition at P/T that same % of fuel that is being added at P/T to compensate is ALSO added to your WOT fueling as well--as a lean safety---This added fuel can make your engine fat and lazy at WOT----Tuning with HP or EFILIVE is the only way to correct both the leaness at P/T and the richness at WOT---all caused by your LT's
LT's will eat up front 02's--In the LS days there were some fixes like installing the rear 02's onto the front locations as the rears are more sensitive---however there is no 100% fix----Also you can alter the 02 switching points to try to compensate for the erroneous 02 readings---The front 02's only control your P/T fueling--unless you have a lean condition where the EM is adding fuel to compensate---Whenever you have a lean condition at P/T that same % of fuel that is being added at P/T to compensate is ALSO added to your WOT fueling as well--as a lean safety---This added fuel can make your engine fat and lazy at WOT----Tuning with HP or EFILIVE is the only way to correct both the leaness at P/T and the richness at WOT---all caused by your LT's
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Thread Starter
Racer
Joined: Feb 2013
Posts: 254
Likes: 5
From: West coast Canada
Thanks for the reply, many points I never knew, it will be worth ordering an extra O2 online then for when I'm back to the car for a few days in a couple weeks just in case that one **** the bed; if not I'll have a spare.
One up here is a week away so could potentially screw me if it has failed
One up here is a week away so could potentially screw me if it has failed