45 messages,
Last post on Jan 30, 2013 at 6:14 PM
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Chevrolet Impala, Sedan
Mar 16, 2012 (5:48 pm)
MY HUSBAND HAS BEEN A MECHANIC FOR OVER 40 YRS CERTIFIED....fOR WHAT THAT'S WORTH WITH THIS IMPALA. 2002 3.4 IMPALA..
PARTS WE REPLACED:
IAC
TPS,
CRANK SENSOR 24X
FUEL PUMP
FUEL INJECTORS (6)
PLUGS/WIRES.
WE DID A WHOLE TOP END REMAN, THERE IS NO VACUUM LEAKS. THE ENGINE IS RUNNING GREAT AND SOUNDS GREAT ONLY WHEN YOU HOLD THE THROTTLE OPEN. WE ARE STILL GETTING RANDOM MISFIRES AND THAT'S THE ONLY CODE P300. pLEASE HELP IN OVER 3 YEARS I HAVE SPENT OVER 12,000 ON THIS PIECE OF... BUT I NEED THIS VEHICLE, I HAVE TWO HANDICAPPED BOYS THAT NEED TO GET TO THEIR DR.S APPS
#44 of 45 Stalled start, slightly fluctuating rpms, pf420 inefficiency below thresh
by ctp2001imp
Jan 30, 2013 (6:07 pm)
Every time I go to start my 2001 Chevrolet Impala, it takes at least three tries before it cranks. its giving me what I remembered being a pf420 code below threshold. I replaced my o2 censor before the cat converter but no cigar. I also believe my alternator is falling behind because the brightness of all of the interior and ext lights fluctuates as well.
I was told it was probably a crank sensor but wanted a second opinion before I go spending that money.
#45 of 45 Re: Stalled start, slightly fluctuating rpms, pf420 inefficiency below thresh [ctp2001imp]
by nick2006matrix
Jan 30, 2013 (6:14 pm)
I assume you meant P0420 in your post. I did not see any mention of the crank sensor in this information: http://www.obd-codes.com/p0420
They mention a faulty cat or a faulty O2 sensor. The sensor after the cat is reading the same as the sensor before the cat.