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440 code what do i do
1999 Chevrolet Silverado 1500

440 code what do I do

(1999 Chevrolet Silverado 1500)
Hi my husband has a 1999 Chevy Silverado v6 not 4x4 anyway I was driving an the cel started to flash so we put on a code reader an it came with 305 an 440 I know the 305 is a spark plug but we never heard of evap what do we do because it’s driving terrible an it’s our only vehicle an we don’t have money either btw it has no heat either but not overheating it was driving perfectly an now it really ruff
What seems to make the problem better or worse? Driving
How long have you had this problem? Just started 11/1/19
Tags: chevrolet, silverado 1500
1 answer & 0 comments
Popular Answer
on November 03, 2019

The most important diagnostic code is the PO305 - - PO440 can wait awhile.

Unfortunately the misfire code doesn’t indicate any particular part has failed - it denotes the # 5 cylinder has a problem and it is not properly contributing to engine operations..

Now it could indeed be a misfiring spark plug .. I hope it’s that simple!

However *hands-on* diagnosis will be required if spark plug replacement doesn’t correct the problem.

Good luck!

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General Diagnosis
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on November 03, 2019

The most important diagnostic code is the PO305 - - PO440 can wait awhile.

Unfortunately the misfire code doesn’t indicate any particular part has failed - it denotes the # 5 cylinder has a problem and it is not properly contributing to engine operations..

Now it could indeed be a misfiring spark plug .. I hope it’s that simple!

However *hands-on* diagnosis will be required if spark plug replacement doesn’t correct the problem.

Good luck!

Sign in to reply

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