Going nuts with C6 problems
Thread Starter
Cruising
Joined: Nov 2010
Posts: 12
Likes: 0
Going nuts with C6 problems
I've got a 2005 automatic Z51 vette, two weeks ago check engine light came on, took it to the dealer and they said the 02 sensor on left side was bad, I replaced it on sunday and soon as I started it, the light stayed on and missing very bad, it was either running great one second and bout ready to quit the next, I took it back to the dealer and they said the right side 02 sensor was now bad, so they replaced that one and the light went off, but, they say it is still running rough and has misfires on 1 and 3, they've moved injector, plugs and wires around and it stays right there on 1 and 3, found out the PCM had been replaced about 4,000 miles ago and they are getting ready to do the same thing to it again free of charge but is this gonna fix it? PLEASE HELP! Thanks
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
kind of odd that you need two pcm's in 4K miles (glad it's going to be free). haven't heard of that, but I'll bump this so maybe someone else will comment on it. just btw, how's the battery?
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
I've got a 2005 automatic Z51 vette, two weeks ago check engine light came on, took it to the dealer and they said the 02 sensor on left side was bad, I replaced it on sunday and soon as I started it, the light stayed on and missing very bad, it was either running great one second and bout ready to quit the next, I took it back to the dealer and they said the right side 02 sensor was now bad, so they replaced that one and the light went off, but, they say it is still running rough and has misfires on 1 and 3, they've moved injector, plugs and wires around and it stays right there on 1 and 3, found out the PCM had been replaced about 4,000 miles ago and they are getting ready to do the same thing to it again free of charge but is this gonna fix it? PLEASE HELP! Thanks
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Melting Slicks
Joined: Aug 2007
Posts: 2,641
Likes: 80
From: Florida
Unless the first PCM replacement was defective, I'm not sure replacing it again will help, long term. Seems there's something taking out the PCM unit, and possibly causing the other problems. They need to find the cause. Good Luck.
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Team Owner
Joined: Dec 2003
Posts: 57,408
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From: queensbury ny
The running good/running like crap symptoms you describe should be the 02 sensors.Maybe a weak battery too.Go to auto zone or somewhere like that and see if they can pick up any codes by hooking up the the computer in the car.It's free!Post those codes,if any,here for additional help. Also,the cat going bad might cause the symptoms.Hopefully the new computer fixes it though.
Last edited by not08crmanymore; Nov 4, 2010 at 04:40 PM.
Thread Starter
Cruising
Joined: Nov 2010
Posts: 12
Likes: 0
The running good/running like crap symptoms you describe should be the 02 sensors.Maybe a weak battery too.Go to auto zone or somewhere like that and see if they can pick up any codes by hooking up the the computer in the car.It's free!Post those codes,if any,here for additional help. Also,the cat going bad might cause the symptoms.Hopefully the new computer fixes it though.
Melting Slicks
Joined: Jun 2007
Posts: 2,673
Likes: 9
From: Upstate New York
Bad ground somewhere? I had one, not a Vette, that was always running very rich. Dealer was blaming everything under the sun, wanted to re-replace O2 sensor, catalytic converter, on and on.
Turned out to be a bad engine ground.
Turned out to be a bad engine ground.
Thread Starter
Cruising
Joined: Nov 2010
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Race Director
Joined: Dec 2007
Posts: 19,574
Likes: 167
From: Frederick, MD
What did they replace the PCM for? Maybe a mod that went wrong? Maybe they sold because it had a misfiring issue. Did they look at the bad 2nd sensor when they found the first one bad or did they just do crappy troubleshooting and assume it was broken. Was the exhaust manifolds removed? These days it is better to leave a car alone if it is working good and if you are not good at troubleshooting. Too many electronic parts that can go wrong.
Race Director
Joined: Oct 2010
Posts: 14,475
Likes: 785
From: Las Vegas NV
100% agree with this. I've gone through it with cars in the past. Bad ground cable on the battery can cause things to happen that you'd never suspect is a battery problem.
Melting Slicks
Joined: Aug 2006
Posts: 2,615
Likes: 694
Well yeah the 02 sensors if the running problem, but they are saying that something is frying them or messing them up whatever, and they claim that it is the PCM doing it, the battery has been replaced bout a year before I got it, when the car is at idle at night you can see for example the tail lights real lightly flickering if you watch close, the dome light does the same thing in the floor and stuff, but when you crack the fuel just a little it quits that, like the alternator isn't putting out enough
....i have a 2007 made in oct 2006 with the original battery still in it. the battery was checked and so was the alternator and both were good, i finally gave up worrying about the flickering....it idles at 500-550 rpm......i have no problems with the car.