Need the professors again- Data logs included

[papadoc]

The return to normal did not last long, and my car is now sputtering again with MIL back on and showing the same codes of lean/rich and multiple cylinder misfires. No MAF codes, though I was wondering if that could be the problem upon reseating of the airbox. Here are some codes with a few pulls in second gear:

group2 time group 2 time engine
mass air stamp mass air stamp rpm
g/s sec g/s sec
10.11 51.31 16.36 50.94 3720
9.72 51.84 16.69 51.45 3640
9.5 52.35 16.17 51.97 3560
9 52.87 14.97 52.5 3520
8.75 53.4 14.86 53.01 3440
8.67 53.91 14.69 53.53 3360
41.36 54.43 38.92 54.06 3240
135.53 54.96 135.11 54.58 4640
132.58 55.48 136.72 55.09 5040
135.22 55.99 138.39 55.62 5280
142.19 56.52 144.36 56.13 5520
150.61 57.06 149.61 56.65 5720
159.17 57.55 158.39 57.18 5960
174.33 58.1 173.5 57.7 6200
106.94 58.59 109.75 58.23 5480
7.69 59.11 17.69 58.74 4400
16.22 59.64 24.03 59.25 4360

I have much more in the log; group 32 adaptation % stayed unchanged at 6% and 0.8%.

Failing MAF? Any other thoughts?

This is with 91 octane tune on APR chip.

Many thanks in advance.

[V8weight]

What exactly was done to your car prior to these misfires occurring? I forgot. Your g/s is low, but even. Usually if your MAF sensor has physically failed, you lose one at a time, and one bank will be significantly lower. On the 91 octane file you should have a combined g/s of over 400, you're at 340. Are you 100% sure the air box is correctly seated? Either that or (gasp!) what ever the techs used to plug the intakes while the airbox was off is still there. Can you send me the whole log? It's hard to tell what I'm looking at there. Pellis833@aol.com

[V8weight]

Ok, re-read your other thread. Did they do the entire 20k interval service (ie. spark plugs, air filters, fuel filter etc.)? Did they put the fuel filter in backwards? Hmm.....

[papadoc]

Thanks, email with data log on its way...

[ben916]

what did the tech gap the plugs at?

[papadoc]

Thought of that after searching the forum; I don't think he regapped them, NGK Laser platinum

[MaxRS6]

^ Bummer and hate to hear about your issues. I know the feeling..take the car in for normal maintenance while the car has been running normally..Get it back and BAM!- issues rain like rainbows and unicorns...I wish you luck with a speedy diagnosis/recovery.

[papadoc]

Thanks all! Whole thing made much worse by wife taking in our Yukon XL for routine service the same day, $45 and no issues. "That Audi...."

[V8weight]

I got your email. Nice logs, good job on that. I think we have a misunderstanding....did you remove the airbox lid and re-seat it? That's not what I was talking about. The MAF's are attached to the bottom of the air cleaner assembly, and I'm almost positive they aren't properly seated into the turbo inlets on the pack of the engine, thus the engine is sucking all of it's air past the MAF sensors. This is what's causing your fuel trim codes.

[V8weight]

what did the tech gap the plugs at?

The plugs come pre-gapped to .028 - .029 This is not his problem....

[MaxRS6]

Thanks all! Whole thing made much worse by wife taking in our Yukon XL for routine service the same day, $45 and no issues. "That Audi...."

OMG- I have the same exact situation..wife has the Denali..she rags to me no end about the "in and out service". The Denali now has about 150K miles without any significant issues other than routine maintenance- and it pulls our ski boat back and forth to the lake on a routine basis...ooooooffff

[papadoc]

I only removed the lid and not the entire airbox. I'm a cardiologist and only comfortable working on engines that are running! The new shop I went to has great ratings locally and on the boards, but I know that the service was done by one of the underlings and not the owner (who was aghast that they might have messed something up with my car). I will call the owner tomorrow and hopefully get the car back in to be certain that the MAF's are seated properly. I've learned a lot about our car's engine these past few days.
And I've learned a lot about what a great online community we have here...

[papadoc]

Max, fortunately I have a son who is now driving a Stasis A4 and backs me up at the dinner table! "Mom, you just don't get it..."

[V8weight]

Not to worry, I was just trying to figure out if we were on the same page as far as seating the air cleaner is concerned. Regardless of the shop's experience, it's easy enough to improperly install the air cleaner. When I was putting Kyle's car back together last weekend, it took me three tries to get the thing properly seated. It's all to easy to have it misaligned and never even know it.

[4everRS]

OMG- I have the same exact situation..wife has the Denali..she rags to me no end about the "in and out service". The Denali now has about 150K miles without any significant issues other than routine maintenance- and it pulls our ski boat back and forth to the lake on a routine basis...ooooooffff

Good news for me is that tomorrow a local Gm dealership is dropping the engine of my wife's Acadia for an oil leak on the timing chain cover. It's under warranty which is also good news, but in a way bad news as my car keeps costing money.

[V8weight]

Good news for me is that tomorrow a local Gm dealership is dropping the engine of my wife's Acadia for an oil leak on the timing chain cover. It's under warranty which is also good news, but in a way bad news as my car keeps costing money.

Soooo....did replacing that trans filter O-ring straighten your car out? I need closure...

[4everRS]

Soooo....did replacing that trans filter O-ring straighten your car out? I need closure...

Yes it did. Shifts good. I bet your having a little deja vu like me about the timing cover issue. The small amount of things I do, something goes awry. I distinctively remember putting that filter in there and thinking, "hmm must just seal good enough like this?" Guess not.

Check is on the way btw. Sorry for the delay.

[V8weight]

Yes it did. Shifts good. I bet your having a little deja vu like me about the timing cover issue. The small amount of things I do, something goes awry. I distinctively remember putting that filter in there and thinking, "hmm must just seal good enough like this?" Guess not.

Check is on the way btw. Sorry for the delay.

Oh, forgot about that....ya, post hast...quitting tomorrow! Moved my toolbox back to the old shop yesterday...