MAF unplugged = car runs better WTF??

[Zach L]

Went and picked up the car from the stealership this morning ...coilpacks were replaced, but the car was still misfiring on cylinder 2 & 4 now.

I took a look at the diagnostic print out and guess what? ...code is being thrown for mass air meter!

At this point I really believe the MAF is just fucked. I should have a new one on the way soon.

[Zach L]

MAF replaced ....problems persist

I can only think that air has to be getting in or out of the system somewhere after the MAF ...hesitation/misfiring only occur at idle when car is at 20 vac.

I do NOT like taking my car to a shop, but damn it I'm getting close.

[Tempted2Speed]

What you end up doing bro?

Im having almost the same problems as you, I installed my intake and then experienced crazy rough idling. Removed the turbo inlet hose to see theres oil in there, and my MAF might be messed up and Im thinking about what to do and if this is the problem.

[nashbar]

I posted earlier. from my experience with the 2.7T, you have a intake leak. on my s4, I had a maf sensor error and a big tear in the throttle body boot. I know cars with a vacuum leak run better without the maf sensor also.

build yourself a boost leak tester and do some logging. usually takes an hour or so to find and fix a leak.

[Zach L]

Originally Posted by nashbar

I posted earlier. from my experience with the 2.7T, you have a intake leak. on my s4, I had a maf sensor error and a big tear in the throttle body boot. I know cars with a vacuum leak run better without the maf sensor also.

build yourself a boost leak tester and do some logging. usually takes an hour or so to find and fix a leak.

Late reply, but how do I go about doing this?

[nashbar]

start with logging, then google "boost leak tester". some silicone, some PVC, fittings and an air compressor... that's a fun Friday night...

[golfix]

Hello there,

I'm from Romania, and i have an mk5 gti 2006. I have same problem as you had. "MAF unplugged = car runs better WTF??"

Can you please tell me how did you figurred out this problem?

I have also change the plugs,coil packs, pcv,dv,n75, maf sensor is new, but the problem persist. Rough idle and missfires on cyl 4 and 2 under WOT.

When i plug the maf out, the cars idle much better and there is not any missfire under wot,the car runs much smoother.

Waiting for your response.
Brgds,

Alex.

[Zach L]

PM sent.

It was not a boost leak or vacuum leak. I've NEVER had either of those. Around the time of this post I think I scrubbed my intake valves shortly after. Also replaced the intake manifold flap motor (specific code for that) and the fuel low pressure sensor (specific code for that as well).

Replacing the injectors and cleaning the intake valves did the most good for the bumpy idle. I replaced the injectors when I cleaned the valves so I don't know which was the biggest help, but the probelm was bad enough that I'd say the injector was the likely cause of the problems. There is no specific code for faulty injectors, so if you have a bad injector you will get codes for many things other than the injector... mostly misfire codes, but also maf code if bad enough.

Injectors in these things are not the stoutest units. I have been running Techron injector cleaner every 3rd tank since 85k miles and have not had a proble (currently at 120k miles). I purchase a set of injector with 20k miles on them for $85 for the whole set. That's the price of one new injector.