Just when things were going well the car threw a little fit yesterday. I was able to drive about 20 miles further, shut down for my meeting and start, drive home about 40 miles. The car sounds like the passenger turbo is overspinning with all the boost leaking out You can literally hear all that, like a waste gate is opening. As long as I kept my foot out of it the car ran "fine". It didn't like idling very much.
The codes are P0103 Hot Film MAF Sensor and P0430 Cat Conv Efficiency Bank 2.

I've yet to get under the car to see what I might have jarred loose. Obviously the MAF sensor could be the culprit with the coincidence that I was just in there.
Thoughts?

 

It is probably an exhaust leak that is causing the P0430 error.

Don't know the history of the car but with my Turbo whenever the exhaust system had to come off the tech made it a point of replacing the metal o-rings -- one per side -- that sealed the turbo to the exhaust manifold. He said many reuse those but they don't seal well when reused. Porsche might even call for them to be a one use item.

Not sure what you mean by " Obviously the MAF sensor could be the culprit with the coincidence that I was just in there." but whenever something odd happens last thing touched is always suspect. And if you were around the MAF, had it out, there's a chance the connection is poor, or even a pin in the connector broke of a wire in the hardness broke. The harness is going on 17 years old and the Turbo engine compartment is a harsh place for wiring. When working on older cars one has to be very gentle to avoid possibly causing a wire in the harness to fracture.

As for the heat, I installed a 2nd fuse in my Turbo which allowed the engine compartment fan to run all the time the engine was on in an effort to keep the engine compartment temperature lower and thus (hopefully) reduce the effects of higher temperature exposure to the harness and other hardware in the engine compartment.

You need to ensure the exhaust has no leaks. You need to ensure the intake system has no boost leak. Regarding this the techs told me often what happens when the intake system is disassmbled upon reassembly an intake hose will have a loose flap of rubber that when the intake hose is installed this flap of rubber gets bent back. It will not leak at first but under boost will leak. It is very important the boost hoses go on and form a tight seal against pressure leaks.

You need to carefully check the MAF and its wiring lead, connector and that of the harness for any signs of something amiss. While I never had the MAF out of my Turbo with my Boxster the MAF connector had some kind of latch mechanism as part of the connector which was very tricky to undo and tricky to reconnect and to get the latch to fully engage. If it doesn't the connectors can come apart and it doesn't take much for at least one pin/socket to develop a marginal/intermittent electrical circuit. Two possible causes of the MAF error code is the wiring is damaged or the sensor is unplugged. It can also just be bad. The MAF on my Boxster went bad but the Turbo MAF was good when I sold the car with 161K miles on it.

 

what did you mean: "jarred loose"? there is some contextual info missing lol.

try disconnecting the maf and driving a bit. reconnect the maf and reset the TB after you reconnect the maf and see how it runs. the maf cannot be easily "jarred" as there are pressure sensitive snap into place connections. its either connected, or not.

.. and what does "it doesn't like idling much" mean exactly? you don't make this easy lol.

 

If it was easy, everyone would do this! Lol
i changed plugs and coils last weekend, so i took the intercoolers off and, apparently, a leak on the pressurized side of the intake could cause that error. Perhaps i missed something putting it all back together.
i did take off the O2 sensor that was in the way of the coil, could be that too.
The exhaust hasn't changed in quite some time, so i don't think anything happened there.
i have not knowingly touched the MAF or any associated wiring.
The noise of the turbo spooling loudly with no boost seems odd to me, which leads me to something on the intake side of things.
You all will have to sit in suspense until the weekend and for that i apologize. Lol

 

Good stuff. I suspect you are correct on the intake hoses. I think i can get to everything pretty easily to verify.

 

Whenever the intake hoses/pipes are removed, you should do the "quick" boost leak test by applying air pressure to the intake after removing the MAF. There are various tutorials here to show you what fittings you need to collect from home depot to perform the test. Initially test at 5psi to recheck your work and to verify that it holds pressure. Any obvious leaks will either be heard, or cause the pressure gauge to drop very quickly to zero.

 

if you disconnected the hoses at the ic's?? that's the first place i would look. you have a leak and that's the clue that the leak is at the hoses from the i'c's - turbo's. simple leak, maf is probably fine. best to really TUG on ALL intake hoses anytime you do this. not enough to just re-clip the clips. GL with it.

i never "re-test" anything when the intake is "opened". i just make sure all is buttoned up properly.

 

The reason I suggested to test for leaks after repairing was twofold: To verify a correct repair, and to verify the integrity of other components that could have, over time, induced a leak. Back when I was working on these things, I took the mindset that it was easier to spend a minute or two (literally, when necessary tools are already nearby) to retest and verify the correction than to have to deal with a return visit by the customer.

 

Yep, drivers side intake hose popped off the IC. Easy Peasy. Thanks for everyone's input!