I found An "L" shaped rubber cap with a sponge inside on my garage floor. Since then my check eng. light has been on. Bought a new gas cap as per Auto Zone Tec. I think the error code is related to th


Asked by Feb 19, 2017 at 02:33 PM about the 2000 Lexus RX 300 AWD

Question type: Maintenance & Repair

I think the P0400 error code is related to the "L" shaped rubber cap I found on the garage floor. I can't figure out where it goes. Changing the gas cap had no effect.

3 Answers


That trouble code is for the EGR system. Nothing to do with the gas cap. Possibly a clogged or malfunctioning EGR valve. HTH. - Jim


This is what I found on my garage floor. It had a sponge inside. I think it might be related to the Check engine light. I can't figure out where it goes or what it is.

1 people found this helpful.

Hmmmmmmm, not exactly sure what that is. But I did some more reading on your Lexus and it seems that you don't have an EGR (Exhaust Gas Recirculation) valve. So now I'm puzzled about what that code means on your vehicle. I'll have to do some more digging! -Jim

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