# check engine light on?



## al98 (Jul 3, 2004)

Hello all,,,newbie here. Anyways,,,I have a question: I drove my 2001 Sentra(1.8),,without the gas cap on just right(for 1 1/2hrs) last week and you guessed it---the check engine light came on. The light was on for at least a week. Having a scanner, used it,, and the resulting PO430 error code.The code says: Catalyst system efficiency below threshold(bank 2). I then used the scanner to 'delete' the code. The past 2 days the car purrs like it always does. My question is--- did the cap not being on right cause this code(PO430), or was it something else? Thanks!


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## sideways ed (Jun 17, 2004)

its probably because too much air was going in


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## xxMIKExx (Jun 30, 2004)

al98 said:


> Hello all,,,newbie here. Anyways,,,I have a question: I drove my 2001 Sentra(1.8),,without the gas cap on just right(for 1 1/2hrs) last week and you guessed it---the check engine light came on. The light was on for at least a week. Having a scanner, used it,, and the resulting PO430 error code.The code says: Catalyst system efficiency below threshold(bank 2). I then used the scanner to 'delete' the code. The past 2 days the car purrs like it always does. My question is--- did the cap not being on right cause this code(PO430), or was it something else? Thanks!


Yep, having your gas cap off will throw your check-engine-light. Had a long discussion with nissan about this one.


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## chimmike (Oct 17, 2002)

it'll go off after a few days. it comes on because the system is pressurized.


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