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Camry False Check Engine Light From Gas Cap

Ben Jammin
09-21-2010, 02:18 AM
Camry Beware if the gas cap is loose, or the seal is compromised the check engine light will come on, and when tested will give a code for Oxygen Sensor. Tightening the cap may resolve the issue, or purchasing a new cap at any auto store.

It makes me wonder how many poor souls took their Camry to the dealer and paid $300 for a new sensor when it was just the gas cap, and of course, I'm sure the dealers are well aware of this anomaly.

Always check the basics before paying for an expensive fix, perhaps someone here on the forums might have the simple, and inexpensive answer to your issue.

You asked for it, you got it, Toyota! (70's toyota advertising slogan)


09-21-2010, 08:34 AM
What scan tool did you use to get what code specifically?

Brian R.
09-21-2010, 10:15 AM
The code for a loose gas cap is P0440. This is not a false Check Engine Light, but a meaningful code for a defective (or loose) cap and other types of evaporative emission system leaks. See this post ( in the FAQ thread for descriptions of the codes and some causes.

09-21-2010, 10:28 AM
I don't know how anyone could confuse any EVAP code with an oxygen sensor?

Brian R.
03-10-2011, 12:22 PM
This is the only thread on this subject allowed. No others will be kept. Spam on this subject or any other will not be tolerated.

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