ok, so I brought my (08 w/2455miles) car back for the second time due to Engine Light issues.. Codes thrown were P0171/74. They contacted GM both times and now want to replace the MAF.... They also told me that this they are starting to see this alot and have/are redesigning the MAF.. Anyone here this or have had similar issues??

To date the dealer has been great to deal with and I don't doubt their story...

 

I have an 06 with 6300miles - never had a check engine light other than once for a bad gas cap seal.

 

It's happened twice to my buddies 08 within the first 4000 miles. It was repaired and came back again. Dealer said they were told there will be a TSB issued one of these days.

 

been to dealer twice now for the same light, told me it was my dipstick.......

 

5000 miles here.... bad gas cap only check engine light issue ....

 

Well this is somewhat alarming to hear. I've only got about 1085 miles on my '08 as of this morning and no CELs as yet. However I wonder if I'm heading for this MAF problem soon, as I've noticed some pinging on acceleration at highway cruise (could be lean tip-in if the MAF isn't doing its job properly). Hmmm...

 

Those codes are for both banks running lean. Ask them what the grams per second at the MAF is at idle. And what the GPS is at idle of another vette there without the check engine light on.

There are several things that can cause those codes, clogged injectors, bad MAP, bad MAF, bad fuel, modified intake, modified PCV system...

I had those codes once on a car I was working on that drove me nuts for several days. I eventually found two identical cars, put all three side by side and this one throwing the codes had slightly less GPS at idle. Real slight like 4.8 compared to the other two were both 5.3. Swapped the MAF and the problem followed the MAF. Then after a short run time, the known good MAF started to decrease down to 4.8 and throw the stupid codes again. Long story short, the thing turned out to have an aftermarket air cleaner that was shedding tiny fibers onto the MAF hot wire. When the hot wire got fuzzy, it would read less air, PCM would give it less fuel, and blammo it would be running too lean at the O2s and trigger the code.

So I think in your situation the MAF is one guess, but I'd really base the diagnosis on scanner readings compared to a car that is not throwing that code.

On the car above with the tip in detonating. I wouldn't worry about that, so many do that normally especially if you don't have 93 in that area.
One thing that will help is some Techron top engine cleaner and a good highway wide open blast. Just the tiniest amount of carbon build up in a high comp engine will give you that detonation. Chevron and GM Parts both have a good Techron based top engine cleaner. Put one in a full tank of premium and give it a few full throttle blasts. That usually reduces detonation in a lot of cars and trucks.

 

Nope, no 93 for us losers here in CA - and 101 unleaded is $5-7/gallon in 5-gallon cans. With only 10xx miles on the clock, I'd be shocked if there were any significant carbon deposits, but I suppose anything is possible. The work-around I've found at least is to roll into the throttle on the highway instead of stabbing it to accelerate. Rolling into it does not elicit the ping.

Bah, I'll just take your advice and not worry about it until it starts setting a DTC (if ever).

 

got the same light @ 500 miles. dealer cleared codes and said both banks were running lean. put cleaner in the tank and filled her up before doing some serious road time. no further issues as of yet. need to watch this on the '08's - may be a TBS in the future