991 GT3 Engine Fault light

[adamGT3]

Ok so I've had my 991 GT3 since September 2014. It was delivered in early February but I luckily chose to wait for 1st of March for the new reg just before the stop sale.

The car has been an absolute dream and lived to all my expectations however I keep having the Engine Fault light appearing every few months! It keeps coming back to the same fault

1. P0491: SECONDARY AIR SYSTEM BANK 1/2

Am I the only unlucky GT3 owner having this issue?

My car is stock but I have fitted the Sharkwerks bypass which I truly love but I know several people who have fitted the bypass but they don't seem to get the same issues. The car was initially looked at by Porsche East London but I've had it taken to Reading (where it is right now) on the last 2 occasions

Just waiting to hear back from Porsche but has anyone had similar issues

[mollytherocker]

I would be interested on Porsches stance on this. Are they washing their hands of it because of the exhaust?

[adamGT3]

They haven't yet (based on my pervious issues) but it is possible that could use it as an excuse not to investigate properly

[av185]

Hi Adam I know RSVP111 has Sharkwerks fitted on his although may have now sold for his RS....may be worth an e mail as he may not pick up this thread. Good luck...

[Fl0pp3r]

Better yet, why not drop the guys at Sharkworks a line, I'm sure they'll have an idea...

[adamGT3]

Thanks av185, I'll drop him a line also. I already know a few on here who have it with no issues

Fl0pp3r I spoke to Alex at Sharkwerks and in their experience nobody has ever come back with that issue with over 250 bypass installs

[RSVP911]

adamGT3 said:

Thanks av185, I'll drop him a line also. I already know a few on here who have it with no issues

Fl0pp3r I spoke to Alex at Sharkwerks and in their experience nobody has ever come back with that issue with over 250 bypass installs

Hi Adam - Sorry to hear you have an issue - it it just a warning light or do you "experience" physical symptoms ? My car as pointed out also has the SWBP and works a treat I'm afraid - sorry .

[adamGT3]

RSVP911 said:

Hi Adam - Sorry to hear you have an issue - it it just a warning light or do you "experience" physical symptoms ? My car as pointed out also has the SWBP and works a treat I'm afraid - sorry .

Thanks RSVP911,

I was just about to drop you a line. The car drives fine with no issues just the amber 'Fault possible to drive' warning, it could just be a technical glitch in the car, when I took it to East London they tried to blame the bypass which seems ridiculous and from then on I only deal with Reading.

[gtsralph]

Sounds like they need to chase leaks though vacuum lines and pumps, not something PIWIS is useful for but I would have thought Reading would have skills to do this.

The standard exhaust could be involved as it is switched between sport and normal by vacuum and the vacuum lines could have become loosened during the Sharkwerks installation.

[adamGT3]

OK so I've had Porsche Reading have a detailed look at the car just in case it happens to any other owner. See below:

"Essentially the air injection system which operates during the initial heat cycle stages leaves deposits of carbon during this 'warm-up' phase. Now being a GT3 it is essentially a race car for the road and normally during driving, these deposits will clear away naturally; however, as the GT3 is only really running properly when it is being driven pretty hard, sometimes these deposits are harder to dissipate and as such continue to build up and cause a blockage in the system. This is detected by a loss in induction by the Engine Management System and thus brings on the warning light.

There are 2 ways which these blockages can be removed, the first is straight forward and involves essentially giving the car a really good drive (driving it hard) and if this doesn't work (in this case it won't probably due to the amount of build up) then we have to manually clean them out by hand and pressure wash the manifolds through.

I have attached some photos below, if you look at picture 1 below, the centre biggest shiny entry port, you can faintly see the carbon deposits built up inside, this is the cause of the issue as I have explained.

So, How do you stop this happening again I am sure you will ask....
The essential answer to this is, if you have or know the car has done a fair amount of town driving and been used gently for a period of time, for want of a better phrase, you need to give it a good thrashing every now and again or else it potentially would re-occur because as I said at the end of the day, it is a road going race car and needs to be driven hard a fair amount of time to really keep the engine running smoothly."

[RSVP911]

Thanks for sharing - very interesting

[nxi20]

Italian tune-up fixes German over-engineered complications; got it

[keep it lit]

nxi20 said:

Italian tune-up fixes German over-engineered complications; got it

[rosino]

I guess this should mean that instead of "one careful lady owner, never tracked" come time of resale we will get.. "Regularly thrashed and used as meant to by the good boys of Porsche Motorsport".

Very good. Already planning my Sunday morning blast as part of my maintenance package.