2004 Toyota Corolla P0300-0304 P0171

CTRAINCHEN

MEMBER
2004 TOYOTA COROLLA
4 CYL
2WD
AUTOMATIC
67,000 MILES

Hi, the scanned OBD II code shows: P0300, P0302, P303, P304, P0171. The abnormal behavior is: when engine is idling, I feel the shake of the car body (probably caused by engine) in back and forth direction, especially when engine becomes warm. What could be the root cause of this error? Thanks.

Saturday, September 12th, 2009 AT 10:41 PM

1 Reply

MMPRINCE4000

MECHANIC
8,548 POSTS

The P030x errors are misfires, so either the plugs, and/or coils. Also possible a fuel pressure issue.
The P0171 error is a lean condition.

First have fuel pressure measured with mechanical gauge, if OK, then replace plugs, use only Denso or NGK Iridium. If problem persists, have the coils tested.

Also check the battery ground to block, make sure it is clean and tight.

It is also possible that you have a clogged convertor causing all the misfires. You may want to check that first.

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Monday, September 14th, 2009 AT 9:09 AM