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Engine runs rough at idle, slight acceleration hesitation

(1999 Ford Taurus)
in Inver Grove Heights, MN on February 13, 2011
car kind of shakes at idle. replaced spark plugs, no change. when reving motor in park, there is a little hesitation in accelaration of motor. do not notice as much when reving after rpm's are up. Goes down the road ok, but notice hesitation when accelerating from stop. Check engine light was on, went off after replacing plugs while battery was disconnected.
Displaying 3 answers & 3 comments
Popular Answer
on February 13, 2011
You do not have to wait the trouble code is stored in the computer. take it to a parts house that will do a free scan of the computer and make sure you get the codes. Then post them on this site.
on February 14, 2011
And what the part store will do with the live data without a dtc??

on February 14, 2011
Nothing, I said pull the codes so maybe that will lead to the problem. Codes are stored in memory Zee.
on February 14, 2011
You do not have to wait the trouble code is stored in the computer - you said.
So why should he get a scan test before the DTC / CEL returns? Battery disconnect resets memory and no real driveability code could be retrieved before CEL returns.

on February 13, 2011
I suggest a computer diagnostic when the CEL returns. It might be a bad MASS Air Flow Sensor, but without the diagnostic it just a guess.

on February 22, 2011
The check engine light was on because the PCM saw a reading it didnt like. The engine shake is probably due to a Missfire. You will need to run a diagnostic scan to see whats going on. Im sure the check engine light will come back on.
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