CEL for 171/174
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 826
Likes: 69
From: Seoul Korea
CEL for 0171 / 0174
Well, every since I started my 03Z in the delivery room from picking it up, have had this issue. Someone give me/dealership some ideas of what is wrong. 1st time they said it was cause my MAF had oil on it from my Blackwing CAI. 2nd time (after the codes came back) they said it was the quality of fuel I was using, and pointed me towards Top Tier fuels..... come to find out that is what I was using, and it came back on. They also tried a new MAF same problem. The only other upgrade I have is the Borla cat-back. I have heard a couple say that it was cause of the upgrades and that I need a "TUNE". I am no stranger to modifing cars, I can't understand how that could be the case. The MAF will read what it reads and adjust fuel accordingly. Any other ideas or dis-agreements or agreements????? This is getting old expecially since everytime I have to go to the dealership it's over 150miles round trip. I am about ready to return this car under the lemon law, but I love it tooooo much and it has been my dream forever, I just want it fixed
ty
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Last edited by HisandHerZ06; Sep 18, 2006 at 07:53 PM.
Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 448
From: Atlanta metro Ga.
Wow, that's ridiculous you've had to fight this for so long..
Make sure you have NO leaks on the back-side of the MAF. Unmetered air will play havoc.
No way are the cat-backs causing an issue.
And at your altitude, the car would be running rich if anything, not lean.
To satisfy the dealer (before your warranty runs out), but the stock airbox back on, see if the code goes away.
Make sure you have NO leaks on the back-side of the MAF. Unmetered air will play havoc.
No way are the cat-backs causing an issue.
And at your altitude, the car would be running rich if anything, not lean.
To satisfy the dealer (before your warranty runs out), but the stock airbox back on, see if the code goes away.
Last edited by Dan_the_C5_Man; Sep 19, 2006 at 11:57 AM.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 826
Likes: 69
From: Seoul Korea
I do not have the stock box, bought it with the blackwing already on it.
I may be thinking backwards here, but leaking "metered" air would cause a rich condition...... computer sees an "X" amount of air, adjust fuel accordingly, if it lost some of that air it would run rich???? unless wherever it takes its rich/lean readings (O2's?)....... I don't know, I can't think of how air in anyway would cause it to go lean...... can't "ADD" air, lose fuel yes........
Yes, it's a 03Z so it's screenless
THX
JOE
I may be thinking backwards here, but leaking "metered" air would cause a rich condition...... computer sees an "X" amount of air, adjust fuel accordingly, if it lost some of that air it would run rich???? unless wherever it takes its rich/lean readings (O2's?)....... I don't know, I can't think of how air in anyway would cause it to go lean...... can't "ADD" air, lose fuel yes........
Yes, it's a 03Z so it's screenless
THX
JOE
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 826
Likes: 69
From: Seoul Korea
Nevermind excuse my ignorance...... I am used to cars UNDER boost, so the whole air leaking out thing isn't right. Under vacuum (which of couse is my 'Vette) extra air could get in sucked in.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Your MAF is likely the issue, especially since it was like this new. Low speed/idle issue. Can you borrow a MAF with a screen and try it for a week or so? This is a known issue, or at least the dealer should have known. Do they happen to have a used car you could borrow a MAF from for a week?
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Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Try a search, this was around a while ago but as I remember it the screenless MAF was throwing lean codes at low engine speed/idle. It is likely a calibration issue that can be tuned out by a competent tuner. The Donaldson actually may be part of the problem. Have you tried removing it to see if the issue goes away? Here's some links:
Link 1
Link 2
Read post 13 on this one
Link 1
Link 2
Read post 13 on this one
Last edited by vettenuts; Sep 19, 2006 at 06:42 PM.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 826
Likes: 69
From: Seoul Korea
Originally Posted by vettenuts
Try a search, this was around a while ago but as I remember it the screenless MAF was throwing lean codes at low engine speed/idle. It is likely a calibration issue that can be tuned out by a competent tuner. The Donaldson actually may be part of the problem. Have you tried removing it to see if the issue goes away? Here's some links:
Link 1
Link 2
Read post 13 on this one
Link 1
Link 2
Read post 13 on this one
OH WOW, boy, this sure sounds like it, I called the service manager and explained all this to him and he is going to talk to some people, but I am sure if nothing else they will try this before anything else!
THX!!!!
JOE
Cruising
Joined: Jul 2009
Posts: 14
Likes: 0
Clarification of above. I have the Blackwing intake air filter, and a Z06 exhaust, and have been to a dealer who wants to charge $100 to see what could be done to rid the codes 171 and 174. He says it is probably (but not surely) a Mass Air Flow meter. but if not...then we keep on spending money. "could be the oxygen sensors" he says...and there are four of them...for some more money.... I went to a tuner in Anaheim, and he suggested disconnecting the battery for 4 hours so the computer refreshes itself to the increased intake air volume, and therefore will add more fuel...so as not to run lean. I did that, and that did NOT solve the code problem. Then another tuner said "as long as the coolant temp does not go up drastically...the the engine will be fine" My coolant temp runs between 194 and 200 until I idle in traffic, then it goes up to 210 or so until I get moving again...so I don't really think I am running that lean..
Which brings me to my original question in a prior post...will that code constantly being thrown harm my engine???
Which brings me to my original question in a prior post...will that code constantly being thrown harm my engine???
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
Clarification of above. I have the Blackwing intake air filter, and a Z06 exhaust, and have been to a dealer who wants to charge $100 to see what could be done to rid the codes 171 and 174. He says it is probably (but not surely) a Mass Air Flow meter. but if not...then we keep on spending money. "could be the oxygen sensors" he says...and there are four of them...for some more money.... I went to a tuner in Anaheim, and he suggested disconnecting the battery for 4 hours so the computer refreshes itself to the increased intake air volume, and therefore will add more fuel...so as not to run lean. I did that, and that did NOT solve the code problem. Then another tuner said "as long as the coolant temp does not go up drastically...the the engine will be fine" My coolant temp runs between 194 and 200 until I idle in traffic, then it goes up to 210 or so until I get moving again...so I don't really think I am running that lean..
Which brings me to my original question in a prior post...will that code constantly being thrown harm my engine???
Which brings me to my original question in a prior post...will that code constantly being thrown harm my engine???
You are not the OP and the date of the Op is 3 YEARS 3 MONTHS ago...
What is your interest in this?
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 826
Likes: 69
From: Seoul Korea
Let ME clairify for future searches. The INCREASED air flow from the blackwing infact was NOT getting metered by the screenless stock MAF and was making the car run lean at the O2's. Since I have put in the SCREENED MAF I have not once had an issue! NOW the reason a car would not have high temps would be 1) thats why you have a cooling system....... once it reaches a said temp, the car cools it...........duh! and 2) since the codes are on, the computer is dumping an ungodly amount of fuel to keep it from running lean! So, if you have an aftermarket air filter and you see the codes, do what GM did, and put a screened MAF in your car............ If it's good enough for the C6Z and ZR1, GM must have also learned what other VERY smart people have. Don't belive the hype (an internet goofs) and think you will loose HP (infact you could gain, cause you aren't dumping unnecessary fuel into the car). Yes, I know people have "learned" it not to throw codes, so 2 options "trick" the computer to not throw the codes, OR GIVE THE COMPUTER GOOD READINGS TO BEGIN WITH!!!!
