Gettinausernamesucks

I have had an issue with my cobalt throwing P0101 codes since I put the CAI on my car. I did a bunch of research and noticed on the solstice forums that those guys swapped more parts around from tubes to dry and oiled filters only to decide if they put the stock parts back on the issue went away. I was suffering the same issues the solstice guys were having with the MAF being skewed and acting wierd throwing the fuel curve off. It was inconsistant and irritating. After checking the MAF for contaminants and the tubes which were all dry I got frusturated. Well guess what. I found that the silver cover on the MAF sensor is tied to the output pins on the MAF. If it touches anything metal on the cover it will see low resistance ground (if your tube is mounted to metal) on some of those pins and skew the MAF pitching out a P0101 and the fuel curves will be erratic as hell because the MAF frequency is all jacked. The tubes I used were chrome plated and the cover was touching the chrome on the tube and the tubes were grounded to the body. Walla instant nightmare. Factory doesn't do this because DUH factory mounting is plastic!
So if you have a CAI of any type on an SC or an TC and you have issues you need to make sure the metal cover on the MAF does not touch any metal on the tube or you will have issues. The mounting tabs on the MAF are fine they are isolated from the MAF pins.

Terminator2

Good stuff. If you were able to figure that out all on your own than kudos to you. This is very good info considering most of the prototype intakes for the LNF are made of metal not plastic!

IsItFast?

Still waiting on an inventory of the parts you used to make yours . Good info.

Gettinausernamesucks

I posted the list in that thread.

Terminator
Not only does it effect LNF's it effects all alumunium type intakes for any GM vehicle. (solstice/sky/duramax diesel/SC cobalts, hondas, toyotas as well, because all the manufacturers run the diagnostic basically the same and most use the same or a similar MAF design) People have been searching for the answer for this for a while and most times its blamed on air filter oil contamination. Yes that can happen but if you put any type of CAI on your vehicle and the mounting provision is part of the alumunium tube you must make sure the cover on the MAF does not touch the alumunium tube. A solution for that is to dremel the area around the tube mount under the mounting surface for the MAF to insure the cover cannot touch the CAI tube.
P.S. having a good understanding of how the thing is made and functions helped alot in diagnosing the problem. However it took a week or so of head scratching before the light came on. If the cover finds a ground path through the tube it creates whats called a ground loop which can skew the resistive and frequency values of the sensor. If the frequency gets skewed enough the Long Term fuel trim can travel to an extreme limit and the vehicle sets a P0101 which causes turbo and supercharged vehicles to go into speed density backup or what you know as Limp mode.

MapOfTaziFoSho

Would a nice bead of RTV be enough to solve this issue?

an0malous

p0101 is caused by a change in cai piping diameter, and increased airflow past the maf sensor, causing it to go above the maf fail frequency.
5 seconds in HP tuners to bump this frequency from 10000 up to 13000 will make this issue dissapear forever.

If it were caused by grounding, I dont think increasing the fail freq would fix the problem....but it does. every time.

Terminator2

You may be right but he said he used the same diameter tubing as stock, and I am not sure that there would enough extra airflow to max out the sensor with stock turbo stock boost. Iam no expert though. Why don't we ask if his CEL went away after he isolated the sensor pins from the metal.

an0malous

if they are anything like the ss/sc,
the stock setup is a ****hair away from tripping a cel due to frequency as it is,
all it takes is a higher flow filter.

Terminator2

I don't know how close it is to maxing out but that is stupid that it would take a higher flow filter to max out a MAF and throw a CEL. I mean I can understand If your pullied supercharged or higher than stock boost turbo and you are untuned, but a stock ss/tc with a CAI maxing out the MAF that's nuts. Not doubting you, but that is just plain rediculous that thay calibrated it that close to it limits.

an0malous

ss/scs have been popping that cel with just a filter or CAI since day one.
wouldnt surprise me at all if its the same issue.

and yup, its rediculous.
but hey, the ss/tc is also a car that will detect your bolton mods, and remove power so that it doesnt break its 260tq threshold....effectively making it unmoddable without tuning. *shrug*

IsItFast?

Well I was bored and decided to replicate gettinausername's setup. Bang, sure enough - PO101. Didnt take long either. It seemed to trigger after the long term fuel trim's went beyond -25.0, but that may have been coincidental. I need to go reset the code and watch the MAF frequency to see what it does.

However, wow what a difference in sound - it sounded incredible! It almost sounded as though there was a blow off valve the recirc was so loud. Also very impressive performance (for a few miles before the p0101 set).

When I modded the MAF adapter I made sure there was no metal touching anywhere, so grounding is not the issue. I ordered a different part number from Jeg's for the MAF to try that - it should be here next week sometime. Im not holding my breath though.

Another interesting note is that the IAT2 temperatures were HIGHER with this setup than the stock setup. Odd.

Maybe this is the reason it is taking the companies so long to get their cold air intakes out?

Terminator2

Wow, it is pulling a lot of fuel, which means that the ecm believes that there is a rich condition and is telling the injectors to spray less fuel. That is, in turn, causing a lean condition. I believe that is why the OP originally claimed that his gas milage went up. It did but his A/F was much leaner that stock, and we already know that DI is already leaner than 14.7 at part throttle.

Gettinausernamesucks

Terminator
It actually is rich. The ECM is trying to get back to 14.7.
The origional issue I had was causing the MAF to have serious control issues. Very Very Unstable.

Is it fast.
My fuel trims are negative now but stable around -16 in 78 degree air which tells me that the air flow went up significantly (like you have stated) and the ECM is trying to compensate. When it hits -25 its going to pop a P0101.(thats where the cal is set to trip) What I'm going to do next is resist the return line from the MAF feedback to the ECM a little. Not sure how much its going to take to skew it back into the +- 2 window but I'll be working on it this week. I'm not sure if this will work as I need to verify whether the output back to the ecm is a true voltage or an actual FREQ. If its a freq its cal time or a rework to the air flow hole into the MAF.

I think the IAT 2 temps are up because the turbo low speed effeciency went up so much and were asking the CAC to absorb more heat as the turbo spools up significantly faster. I'm really pretty stunned the air flow went up as much as it did as the new pipe is a few MM smaller in diameter than the origional pipe. This indicates the air filter is a restrictive ******.

AS of right now I'm not popping a code. But last time it was 94 degrees so That may be part of the issue to. The FT may go more negative with an increase in air temp. I'll have to watch it for a while.

If you guys have any opinions please pass them on. (here I'll get this one out of the way for you. "HP Tuners")

anomalous
Theres certainly the possibility your right as the window is 12500 HZ stock and I've heard of guys saying the MAF is extended beyond the cal limit in the PCM and thats when it throws up on itself. Even though the sensor is capable of 65000 HZ

IsItFast?

I normally see FT in the -14 to -17 range, before I did this. The computer is doing a resonable job keeping the AFR right at 14.7, but it just gets to be too much fuel pulled, and pops the code.

The CEL doesnt come on on mine, I just notice the power loss and no boost, use the scan gages to check for codes and come up with the p0101, so I reset it live and keep driving.

Im going to return mine to stock today, as I am also having some trouble with low-rpm misfires (that were there before) and they have gotten worse.. so I need to take the car in.

Once its back I should have spectre part # 9405 in from Jegs (http://www.jegs.com/i/Spectre/865/9405/10002/-1) - this is a different MAF adapter that has the GM rectangle style adapter, and several tubes to restrict the airflow, so I can experiment with that next week.

Gettinausernamesucks

I found a source that sells a MAF tweeker that is a harness inline. I'm going to look into it. It will allow us to offset the maf freq to scale it back into the proper window. ZZ performance has it listed on their site.

I had a little trouble with an occasional Missfire also. I used a can of lucas fuel treatment in it and adjusted the plug gaps to .030 from .032 and it hasn,t missed since. Crossed fingers.

Is it fast
Thats intresting that you commented on the -16 to -17 stock. I never checked that before I changed. I know if you get a soft P0101 the engine will go into reduced power and hold the wastegate open. You also won't get a CEL unless it sees it twice in a row. Intresting.

IsItFast?

Let me know how that goes. I should note the -16 to -17 was after the hahn 3" catback, before it was around -11 to -12, sometimes as high as -14.

Gettinausernamesucks

I stopped and got a production MAF sensor on the way home. I'm going to mess with the airflow through it first I'll let you know how that goes.

TurboTechRacing

iTrader: (24)

Exactly, it all comes down to the pipe diameter at the MAF. The air velocity must be held close to what "stock" would be...

Kennyspec

I am having the same problem. my car is turboed LSJ and the MAF is in a 3 inch pipe. I thought i was cooking the MAF with 240*F air temps. (pre intercooler) maybe it is grounding out........funny thing is when i bought a new MAF all the problems went away for a month or so.

Gettinausernamesucks

Turbotec
Yes I lost about 3 MM of ID on the new tube and That appears to be just enough to push it over the edge. The velocity went up so it thinks its flowing more air at cruise when reality its not. (so its throwing more fuel at it) I did a back to back test with the new sensor and the stock setup and the CAI and the LTFT is -14-15 on the stock box and -17 with the brand new sensor. On the CAI That must be high enough its trippin it over the edge in some conditions.
I did a fuel trim reset and relearn each time.

Gettinausernamesucks

Problem solved!!!

I moved the MAF housing closer to the air filter by swapping it with the first straight piece below the upper elbow.(I just traded the MAF housing with the first straight piece) MAF is stable now at -5 short term and + 5 cruise. (it popped a code this morning before I altered it at -3 short term and -20 cruise) The exhaust popping and snapping in first gear is gone to. It sure ran crappy when I first started it until it went into closed loop though, then all the sudden BAM up it came. Reset the fuel trims and let it relearn and its all good. I had to modify the wiring harness a little to reach the new MAF location now. I just pulled the wires out of the harness and re conduited them. No biggie.

I can't say that I understand the total reason for it but I had suspected some possible MAF reversion issue maybe from the turbo (or the cam phasers back through at cruise) that the stock air filter was dampening out because its so close to the MAF stock. Hell I don't know all I know is it works.

Terminator2

Sorry, I had it backwards; I thought the tubing was larger than stock which would have caused decreased velocity over the MAF and the ecm would be tricked into thinking less airflow and would have pulled a ton of fuel to compensate causing a lean condition

Gettinausernamesucks

Thats ok
I'm not here to criticize, I'm always open to what others think. I've been doing this stuff 20 years as a full time job and I learn something new every day from someone else. Thanks for all the input guys. Now that its acting normal I can slap a tune on it. I would rather get it right stock first instead of trying to bandaid a hardware problem with a tune.

Terminator2

The distance from the filter to the MAF must be very critical for the LNF, and I can see where the turbulance of the incoming air would effect the reading. I hope you finally have your issue solved.

IsItFast?

Thats a great way to go about things, it can prevent untold problems down the line! I will try this fix sometime soon and see if it works for me too.