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Internal fuel filler tube flap

When you take your gas cap off, usually there is a flap that you press against to insert the hose into your gas line. We just bought a second hand 2003 Toyota Matrix and there is no flap.

Can someone tell us whether it’s supposed to be there?

We noticed it when the check engine light came on and the OBD code was P0442 - EVAP Emission System (small leak). We started looking at the gas cap area more carefully. No obvious leaks around the gas cap.

If the flap is inside the gas line now - is this unsafe?

Do we need to replace the flap?

Can we replace the flap easily? How much will it cost?

On my '05 Camry that flap is not there either. After asking around seems like they didn’t have one from the get go. I touched the inner ring and there is nothing protruding, so mine does not seem to have had it; no base.

As far as the CEl, you might have a bad gas cap or a loose one or something else wrong. You can tighten it and see if the CEL goes away. Gas caps are $5, pretty cheap. If a new one does not fix the problem then you might need more troubleshooting.

You can always go down to your Toyota (or Pontiac Vibe) dealership and ask a salesman to show you the filler necks of whatever is on the showroom floor or the lot. Or you can check at the parts counter. The chances are that this model does not come with a filler flap.

The silly flap does pratically nothing. Its absence is of no consequence. Don’t even consider installing one. Tighten or replace your gas cap and drive for a few days. That might be all it takes to shut off the CEL.