Gas / Exhaust Smell Under Load, Intermittent P0299

[Sharkshark]

Hey, everyone. Long-time lurker, finally registered, desperate for help!


I come looking for some advice to a problem I've been having with no solution in sight. I have a 2007 Mk5 GTI, Automatic with a stage 1 APR remap and a neuspeed crank pulley setup, along with a revision 'D' diverter valve, and everything else is stock besides some lighting changes (LED fog lights as DRLs look so lovely, I have to admit).


Everything was fine after replacing some vacuum lines until a fuel smell started coming through the vents two weeks later, and suddenly became a very strong odor, and only come through during load at any RPM over 2k.

Turning on recirculating air doesn't help at all. Occasionally it will give me an intermittent P0299 (no CEL), and once gave me a CEL with the same code after a hard pull. It builds boost ALMOST as it should, with VCDS graphs to show if needed (near 20 psi in the proper mode, and stock mode doesn't help the issue either). I have no idea what this could possibly be at this point.

Edit: We've changed the gas cap and all fuel injector seals as of today, 7/31/17, though are unfortunately still getting the same issue.

Any help is appreciated. Thank you!

 

[vath]

fuel smell in cabin could be ripped injector seal

 

[Sharkshark]

fuel smell in cabin could be ripped injector seal

Hey, sorry to bump this, but...

Firstly, thank you, vath, for your suggestion. I had my injector seals replaced, though we are still having this issue. We changed the gas cap as well. When I had my tune done, we put in the revision 'D' diverter valve, and we're starting to suspect that it MIGHT be a cause (partially because we're running out of ideas, and luckily it's easy to check). We inspected the HPFP as well, and could not find anything wrong.

We're also going to check the charcoal canister, though that won't explain where the p0299 (underboost) is coming from.

The smell is immediate when applying throttle over 50%, if that helps to diagnose the issue.

If anyone has any extra information, that would be amazing. I'm so desperate to get this fixed and want to keep my GTI. I've always wanted to mod a car, so it's a little discouraging to see so much going wrong with only a few mods...

Thank you!

 

[vath]

You gotta use your nose on this one... (obviously) you need to sniff around the engine bay. Start with cold engine.... Drive it 5 mins down the road then stop and start sniffing around. Could be exhaust leak somewhere too....

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[vath]

Also try driving it with the Recirculation button active.... That should stop an odor coming in from the engine bay.

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[Sharkshark]

Also try driving it with the Recirculation button active.... That should stop an odor coming in from the engine bay.

Sent from my SAMSUNG-SM-G930A using Tapatalk

Either my recirculating air is broken or it's a magical problem where it still comes through the vents.

Any idea what it would be if it still came through (supposedly working) vents with recirculation on?