Evolution Motorsports Stage 2 MAF Failure

[pc18622]

I have a 2002 996 TT with GIAC Stage 2 programming, diverter valves, and Vflow intake from Evolution Motorsport and a Tubi Exhaust. My MAF failed a couple hundred miles after I installed the Vflow intake and it was replaced under factory warranty at the end of December 2005.

Evo said that this was just a coincidence. I assumed that the MAF was probably on it's last leg and the additional air flow put it over the edge -- no big deal. However, it failed again last week (less than a month and 500 miles later) -- at least I think it did.

I was WOT in 3rd gear and the PSM light and ABS light flashed. I assumed a MAF failure. However, the car now drives fine with the ABS and PSM lights on and I am still getting full boost 1.0-1.1 bar) with no CEL under hard driving. I confirmed no CEl light with an OBD II reader. I cleaned the MAF and reset the lights by disconnecting the battery. However, at idle the lights come back on, but the car still drives fine with no CEL light.

First question: What gives?

Second question: I pulled the MAF and the part number reads "996.606.124.00" which previous posts on Renntech.org list is a 2000 Boxster MAF replaced by part number "986 606 125 00." What is the correct part number for a 2002 996 TT MAF?

Thanks for listening. This is frustrating...

[Loren]

Correct part number for a MY02 TT is 996.606.124.00.

Does the Vflow intake have an "oiled" air filter? If so, remove it and wrap it in newspaper overnight to absorb the excess oil.

Have you tried cleaning the MAF with a commercially available electronics cleaner? Do a search here for "cleaning the MAF" as this has been covered by many folks.

[pc18622]

Correct part number for a MY02 TT is 996.606.124.00.

Does the Vflow intake have an "oiled" air filter? If so, remove it and wrap it in newspaper overnight to absorb the excess oil.

Have you tried cleaning the MAF with a commercially available electronics cleaner? Do a search here for "cleaning the MAF" as this has been covered by many folks.

My VFlow came with the new dual panel oil less cotton filter element which is white in color rather than pink. I understand that EVOMS made this change specfically to address MAF failures with the original oiled filter.

I did try cleaning the MAF with QD contact cleaner and reset the ABS and PSM lights. As soon as I started the car up, and it idled, the lights came back, but again, no CEL light, no rough idle, no loss of boost.

Thanks for the suggestions Loren. I need all the help I can get.

I don't blame the VFlow intake ... yet ... but I am going to try reinstalling the stock airbox with BMC filter before throwing another MAF on the fire! I get 1/10 of a bar less boost and more sluggish throttle response with the stock airbox/BMC filter setup which I why I am still holding out hope for the VFlow.

[pc18622]

UPDATE:

So I finally got a CEL code P0102 "115 Mass Air flow sensor - Below Limit."

I still don't know if this MAF failure is caused by the VFlow or not. While it is certainly not impossible, I doubt the MAF would blow after only 1 month and less than 500 miles without some "help." Looks like I'm buying a MAF ...

[Loren]

Check the connector too. A bad connection, shorted or grounded wire can cause that also.

[pc18622]

Check the connector too. A bad connection, shorted or grounded wire can cause that also.

I checked the MAF wiring harness after cleaning the MAF and reinstalling it. There were no obvious defects. I was contemplating using the contact cleaner to clear the male and female ends of the connector but I did not know if that was reccommended. Loren, do think this is safe/would be helpful?

[Loren]

That should not hurt anything.

[CO996C4]

How did your ordeal turn out? I was interested because that was one of the mods I considered but was kind of leary esp at $800! I wonder if it is because of the Giac chip? Have you tried it with stock ECU settings? I personally just kept stock airbox with a BMC filter and stock ECU. Car is very reliable and smooth running that way! I put my Money in suspension and lighter wheels.

[pc18622]

How did your ordeal turn out? I was interested because that was one of the mods I considered but was kind of leary esp at $800! I wonder if it is because of the Giac chip? Have you tried it with stock ECU settings? I personally just kept stock airbox with a BMC filter and stock ECU. Car is very reliable and smooth running that way! I put my Money in suspension and lighter wheels.

The ordeal is ongoing...

I considered the 986 MAF (part number 98660612501) which is supposed to be more resistent to failure. However, I have determined that if the ECU is not reprogrammed to accept this MAF, the car will idle rough and experience fluctuations in throttle response, etc. I could do this, but it would require begging, then paying, a dealer to program the ECU to accept what is essentially the wrong part in my car.

A friend who stocks both MAFs was kind enough to swap the 986 MAF into a TT and described the idle akin to having a lightweight flywheel.

I have opted to replace using the MAF designed for the TT.

MORE IMPORTANTLY, one expert on Evoms products has suggested that running the car WOT with less than a 1/4 tank of gas can cause a "lean" condition that causes the MAF to fail. Sure enough, both times my MAF failed, I was WOT in 3rd gear with about an 1/8 of a tank of gas. I don't know the science behind it, but I am willing to accept that as a possible explanation. Evoms is rumored to be working on a long term solution to the MAF problem, but who knows.

To answer you questions, the VFlow does provide better throttle response and on my car delivers 1/10 of a bar higher boost. I tried back to back runs with and without and with the VFlow to confirm the results. This is of course only my personal, non scientific research! All in all, I am very happy with all of Evoms products including the VFlow. If I wasn't, I would just run the stock airbox/BMC filter and send the VFlow back. It is a worthwhile upgrade and plenty of people run it with a ton more horsepower than me without any problem.

Suspension and wheels are great. I am running H&R coilovers and HRE 540Rs. However, nothing beats adding another 120 horsepower to your car! It is a truly different experience over stock.

Good luck! I will post again when everything is buttoned up...

[Kaizu]

pc18622, thanks for these posts!

I'll be installing the V-flow in the spring time (I have already bought one, but the car is resting this winter). I read quite much threads about it and the MAF problems and "everybody" said there wouldn't be problems with the new oilless filter. Now I'm a little bit scared, hope it works out nicely just with a precise installation and MAF cleaning...because the car will get a lot of track and autobahn driving etc...

EVOMS products aren't really that well-known here in Europe. I'm pleased that the V-flow gives you nice results even though you already had a BMC filter. Maybe I can get some gains too (-01 TT with Techart stage2 530hp) :) By the way, any comments about the sound, did it change ?

The EVOMS company seem to provide most bang for the buck. For example the ~600hp kits from European tuners costs more (okay, weak dollar too) but they usually include more parts...maybe one could say for example that some kits from Europe (RS-tuning,Techart,Sportec etc) are more expensive but with better reliability... I'm a bit bored to read about all these CEL lights and blown MAF's etc!

But if I don't get bigger problems with the V-flow, I'll buy some more EVOMS products in the future too...they seem to have nice solutions and a lot of happy customers. :)

[pc18622]

CONCLUSION

Okay so I put a new MAF in and the car runs buttery smooth again.

I want to say that I do NOT fault the VFlow for my MAF failures...yet. At this point, without more info, it is not fair to say the VFlow is the cause of all things bad for the MAF. I am not willing to say, "I added the VFlow, the MAF failed therefore, it must be the VFlow." There are a number of things that could be causing the failure other than the increased airflow through the intake. The coincidence of the addition of the VFlow could just simply be that.

If you must assign blame, I think a better question in why Porsche/Bosch have accepted a MAF design that is so apt to failure. Regardless of what the "stock is best" crowd chants around the fire, it is hard to make a credible case that the MAF is a durable piece. MAF failures are legend around the Porsche repair bays.

So, as always, speed and increased horsepower has a cost. If you can live with 417 horsepower, you will save money on MAFs. If you enjoy having your car perform better than 99.9% of cars on the road -- and then even better than that -- you'd better buy a pillowcase to put all your blown MAFs, Beru spark plugs, pressure plates, brakes pads/rotors etc. in.

To answer Kaizu's question, the VFlow did not make any significant difference in the engine note. The reason to add this piece is better throttle response and a touch more horsepower.

Good luck all. When my MAF failes again or I get more info, I will add to this post. Until then, I will try not to let the tank get below 1/4 and see if that helps!