CEL and MAF problems

[dpigguy]

First post so be gentle!

Continue to get CEL intermittently with P0171 and P0174 codes. LS3 engine with 1000 miles on same. GM issued TSB (#2048767) that says it is a problem but they do not have a fix. Hopefully they are working on same.

Anyone else have this problem and/or a proven solution yet?

 

[c4c5specialist]

First post so be gentle!

Continue to get CEL intermittently with P0171 and P0174 codes. LS3 engine with 1000 miles on same. GM issued TSB (#2048767) that says it is a problem but they do not have a fix. Hopefully they are working on same.

Anyone else have this problem and/or a proven solution yet?

HI there,
That preliminary document states only that the technicians need to be very thorough and follow diagnostics completely prior to replacing parts.
It states "It is important to complete current diagnostics due to the possibility of having a basic lean condition/vacuum leak."
A few tips.
Making sure the MAF sensor is connected correctly and that there are no breaks in the duct. Making sure there is no contamination on the MAF sensor.
Checking fuel trims and seeing if they change with enrichment of the air fuel mixture.
Checking fuel pressure/injector flow rates/fuel pump volume.
Checking intake manifold for correct torque and sealing.
Checking the vacuum hose to the brake booster to make sure its not leaking and is installed correctly.
Allthebest, c4c5

 

[dpigguy]

HI there,
That preliminary document states only that the technicians need to be very thorough and follow diagnostics completely prior to replacing parts.
It states "It is important to complete current diagnostics due to the possibility of having a basic lean condition/vacuum leak."
A few tips.
Making sure the MAF sensor is connected correctly and that there are no breaks in the duct. Making sure there is no contamination on the MAF sensor.
Checking fuel trims and seeing if they change with enrichment of the air fuel mixture.
Checking fuel pressure/injector flow rates/fuel pump volume.
Checking intake manifold for correct torque and sealing.
Checking the vacuum hose to the brake booster to make sure its not leaking and is installed correctly.
Allthebest, c4c5

appreciate the tips - gives me something to start with while GM comes up with their fix. for them to issue the prelim. document, must mean others have had an issue as well - at least I hope.

 

[c4c5specialist]

HI there,
No question there, as are alot of unnecessary parts being changed which do NOT fix the problem.
Allthebest, c4c5

 

[dpigguy]

Continuing saga - CEL light on after code cleared 4 times in 1200 miles. GM still has no fix but devine intervention has taken over - started the car up and the CEL is no longer on! Checked the vaccuum lines and the like the best I could and all seem okay. Will have the dlr check the fuel trim, etc.

Makes me wonder if its not a cap issue even without the DIC message since they will clear after a few starts on their own. Oh well, such is the life with the LS3.

 

[dpigguy]

well, its back for the fifth time (at 2500 miles) and GM is still working on it - per Detroit. otflotfl
latest guidance is that its a false error signal (duh) and a programing solution is being developed. told to dirve it as is and not to worry. the black electrican's tape solution is looking better and better!

otherwise the car has been flawless

 

[avacorvette]

Don't put up with that. Claim the lemon law. Try and trade it in or sell it with that light on, you would not buy it.
Good luck and give it back.

 

[c4c5specialist]

What?
Its a programming issue.
When it is ready, it will be one hour.
At least they are being honest and telling you the truth.
Allthebest, c4c5

 

[dpigguy]

Actually they

 

[dpigguy]

Actually they are being more then honest in that I have developed quite a conversation with engineers both at BG and Detroit. I am doing some field testing for them as well and they are working hard to fix the issue. I don't think trading in a good vehicle for a PCM programing error is logical or in the cards

Save the wave

 

[dpigguy]

The latest - BG has had me switch fuels - seems the power train guys really think it is a fuel problem vs. a programing issue. On my second tank full of a "top tier" fuel and light has stayed off for over 600 miles - longest since purchase. Was running ExxonMobil, now Chevron - both 91-93 octane. Time will tell if this is truly a fix or just the calm before the storm.

 

[dpigguy]

A final update (hopefully). With the change in fuels, CEL has remained off for over 1000 miles now. Did a survey of C6 owners and found that there was no regional correlation but 25% of the '08 who responded with the problem were running Shell or ExxonMobil. No documented issues with Chevron or other top teir fuels. Granted its was a small sample (approx. 28 responses) but seems to solve the problem - at least for now.

save the wave!