Check Engine code P0171
Safety Car
Joined: Jun 2004
Posts: 3,563
Likes: 2
From: Dallas Tx
That is strange that many vettes don't set those codes and a few will reset those codes right away. Generally Shell is one of the best brands out there, but it wouldn't hurt to try a different brand. Those two codes are very fuel related and if you've always used the same station?
Do they have much ethanol % in that fuel. Anything higher than 10% will set those codes. Those codes will also set if anyone puts E85 in a non E85 car, I've seen that quite a bit. I'd try a different brand of fuel just out of curiosity and to rule that out.
Do they have much ethanol % in that fuel. Anything higher than 10% will set those codes. Those codes will also set if anyone puts E85 in a non E85 car, I've seen that quite a bit. I'd try a different brand of fuel just out of curiosity and to rule that out.
Thread Starter
Heel & Toe
Joined: Dec 2007
Posts: 16
Likes: 0
From: Naperville Illinois
Hi Michrider,
Thanks for the tip. I will try a different brand. I have gone to different stations, but same brand to rule that out station. I am not sure of the % of ethanol but will also check that out too. FYI the CEL is back on and Onstar confirmed same codes. Informed dealer that code went off again. How are other owners experiencing same problem handling this? Are you going to dealer to get reset each time? Continuing driving with light? Let me know. Thanks
Thanks for the tip. I will try a different brand. I have gone to different stations, but same brand to rule that out station. I am not sure of the % of ethanol but will also check that out too. FYI the CEL is back on and Onstar confirmed same codes. Informed dealer that code went off again. How are other owners experiencing same problem handling this? Are you going to dealer to get reset each time? Continuing driving with light? Let me know. Thanks
Thread Starter
Heel & Toe
Joined: Dec 2007
Posts: 16
Likes: 0
From: Naperville Illinois
Update to my issue: I have been in contact with GM customer service but without any results yet. Dearler mechanic advises to drive with light and ignore. He states I could bring in but all he can do is reset until GM advises him on fix. Also side note, my CEL went off yesterday for first time on it's own.
Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
Update to my issue: I have been in contact with GM customer service but without any results yet. Dearler mechanic advises to drive with light and ignore. He states I could bring in but all he can do is reset until GM advises him on fix. Also side note, my CEL went off yesterday for first time on it's own.
6th Gear
Joined: Oct 2007
Posts: 6
Likes: 0
From: Piscataway NJ
I am having a CEL issue also. I was told by onstar that it is a fuel sensor issue but I did not get the code #s. I also use Shell gas. I am taking it to Kerbecks for service on Thursday to see whats up
Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
be sure to post what you find out at Kerbecks or PM me with your data so that I can relay back to BG. thanks!
Safety Car
Joined: Jun 2004
Posts: 3,563
Likes: 2
From: Dallas Tx
Update to my issue: I have been in contact with GM customer service but without any results yet. Dearler mechanic advises to drive with light and ignore. He states I could bring in but all he can do is reset until GM advises him on fix. Also side note, my CEL went off yesterday for first time on it's own.
Just a few other models that someone put E85 in a non E85 car.
Maybe since your area is getting out of winter fuel, the problem will go away.
Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
If the light stays off with a different brand of fuel in there, I'd be leaning toward gas in that area as the cause. I know those two codes will trigger if too high percent of ethanol is used. With winter fuel coming and now going away, maybe the percents got out of whack in that area. Around here, where fuel is generally always good quality and mostly 0% ethanol, I've never seen those codes in any 08 vettes.
Just a few other models that someone put E85 in a non E85 car.
Maybe since your area is getting out of winter fuel, the problem will go away.
Just a few other models that someone put E85 in a non E85 car.
Maybe since your area is getting out of winter fuel, the problem will go away.
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Le Mans Master
Joined: Dec 2005
Posts: 7,753
Likes: 210
From: North Western Connecticut
interesting point - data I collected from CF members shows the issue to not be issolated to the southwest. documented '08 problems in AZ, TX, IL and NJ. most gasoline is shiped via pipeline and is "fungible" or identical regardless of brand. ethanol and brand specific additives are added "on the fly" at the distribution terminal when transport is loaded. so far the information doesn't show a connection with area but clearly sw is a key area with AZ and TX having the most CEL occurences.
Team Owner
Joined: Sep 2006
Posts: 67,022
Likes: 51
From: Beats UD regularly playing 3D chess, and at life
There is a vacuum leak, exhaust leak or O2 sensor causing the code.
I would make sure they go over it with a fine tooth comb to find the cause.
Clearing the code and driving it may cause further problems like a carboned cyclinder, melted cats, etc.
I would make sure they go over it with a fine tooth comb to find the cause.
Clearing the code and driving it may cause further problems like a carboned cyclinder, melted cats, etc.
Instructor
Joined: Aug 2006
Posts: 242
Likes: 50
From: Palm Desert California
Does you vacuum bleed off of you power brake booster over night or 2 nights? mine does and my 06 set off those codes. Should vacuum bleed off? Does not seem like it would without a leak
Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
There is a vacuum leak, exhaust leak or O2 sensor causing the code.
I would make sure they go over it with a fine tooth comb to find the cause.
Clearing the code and driving it may cause further problems like a carboned cyclinder, melted cats, etc.
The TSB put out by GM noted this as well as a few other items to check when the CEL comes on. Dealer has doen the checks several times and I personally did a vaccuum line and device check too. No leaks found but I agree with you and continue to watch for same. May just be a PCM issue that can be tweaked with a reprograming. After having 7 of these in 2000 miles and having the dealer clear each time, don't think any damage is being done but ...........
I would make sure they go over it with a fine tooth comb to find the cause.
Clearing the code and driving it may cause further problems like a carboned cyclinder, melted cats, etc.
The TSB put out by GM noted this as well as a few other items to check when the CEL comes on. Dealer has doen the checks several times and I personally did a vaccuum line and device check too. No leaks found but I agree with you and continue to watch for same. May just be a PCM issue that can be tweaked with a reprograming. After having 7 of these in 2000 miles and having the dealer clear each time, don't think any damage is being done but ...........
Safety Car
Joined: Jun 2004
Posts: 3,563
Likes: 2
From: Dallas Tx
I'm still betting it's gas. There are tons of 08 Vettes around where I live and I've yet to hear of one setting those codes. I have several friends with 08's and they've never heard of it. Gas formulations are very region specific due to EPA regs. Areas high is certain pollutants get higher percent ethanol in the premium. The octane boosting components are real polluters in the EPAs mind. That's why the octane is lower in CA ... Vegas ... and in those areas you often see 10% ethanol.
Another thought, switch to 89 for a couple tanks. That will have less ethanol boosting the octane, if ethanol is used in your area.
Another thought, switch to 89 for a couple tanks. That will have less ethanol boosting the octane, if ethanol is used in your area.
Thread Starter
Heel & Toe
Joined: Dec 2007
Posts: 16
Likes: 0
From: Naperville Illinois
Update: CEL stayed off for about a week and has returned over the weekend. Have used several different brands of gas, Shell, Mobile, and BP from different stations. Only similarity that I have seen has that the code "always" has come on while I have been on the highway. Speeds were not high. 65-85. RPMS were not high either 1.5 - 2.5.
Intermediate
Joined: Sep 2004
Posts: 28
Likes: 0
From: Okemos Michigan
I first got that code when my 08 vert had about 200 miles on it. I took off the gas cap and put it back on, clicking it five times (as told to do by my salesman), and the CEL went out after the second ignition cycle. At about 450 miles it came back on, and would not go out no matter what I did with the gas cap. By the way, the gas tank was about half full each time it came on. After filling the car up with gas, the light went out after the second ignition cycle. We'll see if it comes back on when the gas tank again gets down to half.
From everything I've read on the forum about this problem, GM doesn't have a clue what is causing this problem, but it only seems to be happening on the 08's.
From everything I've read on the forum about this problem, GM doesn't have a clue what is causing this problem, but it only seems to be happening on the 08's.
