These cars are very picky about airflow. The air flows faster into the MAF with it being stuck right there. I think the fault tolerance for running lean is ~5%, some intakes push it out to ~6-7%. It's not too big of a deal. They have "MAF Inserts" to correct the issue. The APR chip just expands the range of running lean... you might be able to hit 10% leaner than expected without throwing a CEL. The car does compensate for it. The reason the air flows faster is much less restriction, kinks, etc... that's why intakes make slightly more power.

Get the CEL checked just to be safe. It could be for something completely unrelated. But yes, you're fine to drive with it.

 

I've had my p-flo intake for at least three years and haven't had any cel issues because of it. I had the united motorsports ecu flash done a fewer months ago and no cel problems either. As DJ indicated get the code read to see what is causing your issue.

 

thank you.

 

I am pretty sure the CEL I am having is related to the air intake, and signals that the engine is now getting more air that before, so the computer thinks it drives lean. This makes no sense to me, since the air goes through the same hose diameter than before, so how could it be more air flow now ?

it's the calculated volume vs rate of the air coming in. review this drawing and the dimensions for the tubing insert. this marginally increases velocities within the maf assembly and actually corrects the rates at the sensor. not much difference in inside diameter, huh? but that's all it takes to get you back into spec.

If the CEL is caused by the air intake, it this a “false positive” ?

no. your fuel trims are off.

Is it okay to drive with the CEL on, and for how long ?

perhaps. as long as the CEL is related to the MAF error. you need to get it checked today or tomorrow. it's free at the part stores; autozone, advance, etc. and will probably take all of ten minutes to get it read. all you need is to report the odbii code to us. for all we know it may be related to the intake air temp sensor (you did reinstall this, right?)

Could a new MAF solve the problem ?

no. vw set the specifications for the air flow. a different/new maf will do the same thing.

What actually does the APR chip flash to solve the CEL issue ? Will it make "immune" to running lean, or will it actually inject more fuel to compensate for the "lean" status ?

like dj stated, it pushes the threshold of error out to a greater degree. the ecu calculates and compensates to some degree with the readings from your o2 sensors to adjust air/fuel ratios.

personally, i'd run with a maf insert even if i was chipped. you can see that there is not much restriction to speak of.

 

le0n, thank you that is very informative.

I looked up MAF insert, but no luck yet, I found a DIY on it but i don't have the tools and work space, I would rather buy one, could you guys point me in the right direction please?

I would rather do a MAF insert than do the APR chip.

Car still running fine. I'll see to get a reading on the error code, and will post it here.

 

20squared is the only company that made one AFAIK, and I don't think they exist anymore. I think the diy route is the only way to go and I believe there is a detailed one on VWVortex. I would just look it up and maybe a shop can maje one for you based on the info given.

 

This is the scan printout from autozone - CEL light on:

6/1/2012
OEM Number for cross : P0068

Definition:
Throttle position and engine load do not agree

Explanation:
The ECM detected that the TPS value and engine lead do not agree with the expected TPS value and engine load.

Probable cause:
-Check engine for vacuum leak
-Check engine condition-Mechanical condition, plugged exhaust or intake
-Transmission condition

On my way home I bought a new battery and replaced it, CEL went out and stayed out all the way home (about 15 miles).

I am going to make the MAF insert and see how that goes.

ANy input on that error code appreciated.

Thanks.

 

P0068 MAP/MAF - Throttle Position Correlation

yeah, most likely it is just that.

i sending you a pm now...

 

http://forums.vwvortex.com/showthre...m/showthread.php?5704808-MK5-Mid-Chassis-Brace-Kit-and-MAF-Insert&highlight=maf

here's the insert for sale

 

^^ good find

 

Thank you for helping.

I sent pm-s to a couple guys for the MAF insert, and also ordered the aluminum tube to make it myself.

Since i replaced the battery I did not get the CEL back (about 100 miles). Oh well ... Weird. I will have the insert in case it comes back.

APR chip might be a future option. I kind of like the thought of infusing new life to my Rabbit. Plus the fun factor ....

I appreciate the help, great community.

 

Update to this topic: 6/8/2012 -- CEL came on after about 120 miles.

I used this link --- http://forums.vwvortex.com/showthread.php?4189770 --- to make a MAF insert, just installed it (CEL is still on).
Now, I understand the CEL is supposed to turn off after a short time, so I am waiting to see that.

On a side note: the insert fits well but it will move once installed I am thinking it might rattle at higher (or lower) rpm-s.

I'm thinking to spray a bit of adhesive on one side of the lip. Of course, away from the MAF sensor ....

 

just unplug the battery for a few minutes to have the system reset. even if the light does eventually go out, it's better to have the system calibrate itself to the new part...

also, today's date in the states is 6/7/2012. where are you located?

 

I'm in Seattle, you are right it is 6/7/2012 ....

I ended up spraying a bit of adhesive on one side of the outside lip of the insert just to prevent it from moving or vibrating.

I reset the CEL and keep an eye on it & hope it doesn't come back.

I can feel a difference in driving with the MAF insert. The car feels and handles more like "stock", a bit less responsive but smoother. Didn't expect to notice such a difference. Interesting.

APR chip might be a fun upgrade. We'll see how the CEL behaves and go from there. But then again, if I start getting the "mod" bug I might find something else after this ....