Please HELP!!! ASAP
Safety Car
Joined: Sep 2000
Posts: 3,572
Likes: 420
From: Taildragers rule! USA1
Put it back to stock. Or sell it in the for sale area where there are a ton of modded C5s that don't run or sell either.
It is illegal to run without cats in the USA. Why would you want to do that?
It is illegal to run without cats in the USA. Why would you want to do that?
Melting Slicks
Joined: Jan 2007
Posts: 2,170
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From: Oilerville Edmonton
St. Jude Donor '08
good luck
Melting Slicks
Joined: May 2008
Posts: 2,606
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From: Rochester New York
Race Director
Joined: Jun 2004
Posts: 19,459
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From: Schaumburg IL
CI 7-8-9-11 Veteran
St. Jude Donor '06-'10, '13
Ok at this point your are getting very frustrated.
Take a deep breath.
#1 it has nothing to do with the cats
#2 it has nothing to do with the tune
Have you verified the O2 sensors are run correctly and the wires have not burned on the headers?
Are the plug wires connected firmly on the coil packs and plugs?
Are the wires connected to the coil packed all plugged in firmly?
If the car was running without missing before the header install them it should should run now without missing.
Take a deep breath.
#1 it has nothing to do with the cats
#2 it has nothing to do with the tune
Have you verified the O2 sensors are run correctly and the wires have not burned on the headers?
Are the plug wires connected firmly on the coil packs and plugs?
Are the wires connected to the coil packed all plugged in firmly?
If the car was running without missing before the header install them it should should run now without missing.
I would be willing to bet it is your O2 SENSORS!!!! You know how I know?? I, with the help of a good friend who is a mechanic installed headers on my car several years ago, and I had the EXACT SAME SYMPTOMS you do with your car, turned out we had the O2 sensors criss-crossed. We switched those and bingo, problem went away and car ran great.
All of the other suggestions about checking plugs and wires, coil packs is also good to look at too. I damaged one of my plugs also and that caused a mis-fire.
I am with VegasVette and the rest,,,, it is not a Tune issue, and has nothing to do with cats or no cats. I drove my car for about a year with headers and NO tune and , yea had check engine light , but car ran just fine.
You really need to find a shop that specialize in Vettes, or GM's for that matter. These Midas/meinke muffler shops only know how to bend pipe and cut/fit exauhst...most of those guys are graduates from Jiffy Lube, and think they have made it to the big time mechanic when they get a job installling exhausts
Last edited by FrankTank; May 24, 2010 at 10:54 PM.
Thread Starter
Pro
Joined: Mar 2010
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From: Navarre Florida
I would be willing to bet it is your O2 SENSORS!!!! You know how I know?? I, with the help of a good friend who is a mechanic installed headers on my car several years ago, and I had the EXACT SAME SYMPTOMS you do with your car, turned out we had the O2 sensors criss-crossed. We switched those and bingo, problem went away and car ran great.
All of the other suggestions about checking plugs and wires, coil packs is also good to look at too. I damaged one of my plugs also and that caused a mis-fire.
I am with VegasVette and the rest,,,, it is not a Tune issue, and has nothing to do with cats or no cats. I drove my car for about a year with headers and NO tune and , yea had check engine light , but car ran just fine.
You really need to find a shop that specialize in Vettes, or GM's for that matter. These Midas/meinke muffler shops only know how to bend pipe and cut/fit exauhst...most of those guys are graduates from Jiffy Lube, and think they have made it to the big time mechanic when they get a job installling exhausts
I have one concern though about going there. They might not take my car cause it is has aftermarket parts in it(intake, predator tune, and now full exhaust) or worse report me somewhere for not having cats.
Race Director
Joined: Jun 2004
Posts: 19,459
Likes: 48
From: Schaumburg IL
CI 7-8-9-11 Veteran
St. Jude Donor '06-'10, '13
Thank you! your confidence that this is an 02 sensor problem makes me feel better. I did research on internet about o2 sensors, their function, closed and open loops and the more I learn the more confident I grow I that that is the problem. I took the vert to another shop today and specifically told the mechanics to check o2 sensors first. i just hope they as turn out to be as honest as they seem, and if they decide to join the club and tell me i need cats then I will take the vert to Chevy dealership and have their mechanics to check it.
I have one concern though about going there. They might not take my car cause it is has aftermarket parts in it(intake, predator tune, and now full exhaust) or worse report me somewhere for not having cats.
I have one concern though about going there. They might not take my car cause it is has aftermarket parts in it(intake, predator tune, and now full exhaust) or worse report me somewhere for not having cats.
I would go on the Southeast section of the forum here and ask for a recommened vette shop near you and have them look at it.Maybe the shop you have it at now will figure it out, but it's up in air (along with your car) I am curious to see what they think.
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Race Director
Joined: Apr 2005
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From: Fremont CA
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
NCM Sinkhole Donor
You stated that the muffler shop installed new wires, so that couldn't be the problem - but that is when your problems began? If that's the case, I would make sure that the new wire isn't defective. Also, any reputable shop knows that they have to protect the spark plug wires from the massive added heat of headers. Did they do this?
Melting Slicks
Joined: May 2008
Posts: 2,606
Likes: 355
From: Rochester New York
Don't be afraid of the dealer. Aftermarket equipment only reflects negativity when it comes to warranty jobs. When its a pay job they should be willing to do what they can to help you out and get some work in. I would first look for a Corvette specific shop or speed shop that specializes in LSX. If there aren't any around your Chevy dealer is a good bet over a mom and pop shop.
Thread Starter
Pro
Joined: Mar 2010
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From: Navarre Florida
This is going to be the next step. Today I decided to try last time and took the car to a place where they have a gm mechanic(obviously not working for gm anymore) People say that if anybody can figure it out that would be them, they do things like rear differentials, electronics, aftermarket parts installs and have gm scanning tools.
i will post the updates tomorrow.
Thanks everyone
i will post the updates tomorrow.
Thanks everyone
Pro
Joined: Mar 2005
Posts: 722
Likes: 70
From: Fla
possible problem
Today I picked up my 01 A4 vert from a muffler shop with new OBX headers, X pipe without cats, and a used flomaster mufflers installed. It sounded incredible and first couple miles on my way home everything seemed fine.
Shortly after I started noticing that the car lost a LOT of power especially in lower rpms, The A4 became much less responsive,(a lot of lag) and sometimes the car would jerk forward without even me touching accelerator. The check engine light came on, first blinking and then stayed on. I did several 0-6- runs (on a closed road) and found that I lost almost 1 1/2 second. (it was 5 flat now it is 6.5) I plugged my diablo predator tuner and red the code, it showed the following code PO300 misfire!? I took the tune of and restored my backup tune and then the vert did not even have power to spin the wheels. It felt more like Honda civic acceleration. The milege went down big time as well!!!
I have a dual cone CAI, and a factory diablo tune in the car otherwise stock. The muffler guys called me earlier during installation and told me that the spark plugs and wires looked brittle and recommended getting new ones. I got only wires but decided to wait with plugs for a few weeks.
Tomorrow morning I am going back there with a lot of questions!!!
I spend 1500$ to gain HP, not to loose it!!! I need you guys opinions and advises as to what it is and what I should do
Thanks in advance for you help!!!
Victor
Shortly after I started noticing that the car lost a LOT of power especially in lower rpms, The A4 became much less responsive,(a lot of lag) and sometimes the car would jerk forward without even me touching accelerator. The check engine light came on, first blinking and then stayed on. I did several 0-6- runs (on a closed road) and found that I lost almost 1 1/2 second. (it was 5 flat now it is 6.5) I plugged my diablo predator tuner and red the code, it showed the following code PO300 misfire!? I took the tune of and restored my backup tune and then the vert did not even have power to spin the wheels. It felt more like Honda civic acceleration. The milege went down big time as well!!!
I have a dual cone CAI, and a factory diablo tune in the car otherwise stock. The muffler guys called me earlier during installation and told me that the spark plugs and wires looked brittle and recommended getting new ones. I got only wires but decided to wait with plugs for a few weeks.
Tomorrow morning I am going back there with a lot of questions!!!
I spend 1500$ to gain HP, not to loose it!!! I need you guys opinions and advises as to what it is and what I should do
Thanks in advance for you help!!!
Victor
Pro
Joined: Mar 2005
Posts: 722
Likes: 70
From: Fla
02 sensors
Thanks for the response, I just tried driving around my subdivsion and discovered that the car stalls constantly, seems like it has gotten worse since my drive home from the shop. I was planning to go back to those guys and show them the car, but I am not sure that I can even make it to their place anymore.
I heard that headers make the a/f leaner, Is there any way to use the diablo predator to at least temporarily fix the problem (like changing a/f mixture to richer?) just so I can get to the shop
I heard that headers make the a/f leaner, Is there any way to use the diablo predator to at least temporarily fix the problem (like changing a/f mixture to richer?) just so I can get to the shop
Burning Brakes
Joined: Jan 2010
Posts: 763
Likes: 0
From: Murfreesboro TN
This is going to be the next step. Today I decided to try last time and took the car to a place where they have a gm mechanic(obviously not working for gm anymore) People say that if anybody can figure it out that would be them, they do things like rear differentials, electronics, aftermarket parts installs and have gm scanning tools.
i will post the updates tomorrow.
Thanks everyone
i will post the updates tomorrow.
Thanks everyone
(I will mark my O2 sensors when I install LTs in my 99 soon)
Race Director
Joined: Jun 2004
Posts: 19,459
Likes: 48
From: Schaumburg IL
CI 7-8-9-11 Veteran
St. Jude Donor '06-'10, '13
This is going to be the next step. Today I decided to try last time and took the car to a place where they have a gm mechanic(obviously not working for gm anymore) People say that if anybody can figure it out that would be them, they do things like rear differentials, electronics, aftermarket parts installs and have gm scanning tools.
i will post the updates tomorrow.
Thanks everyone
i will post the updates tomorrow.
Thanks everyone
I'm not saying we are all mechanics here, but alot of us made this same mistake with same results, so learn from our mistakes.I am now frustrated with this thread, and its not even my car
Its kinda like me lighting a match and burning my finger and sayiing "ouch that hurt" and someone else tells me dont play with fire it burns....then I do it again and again and same resultTell the shop you talked on a forum with several people who have the same car, same results as you are getting, and we changed our o2's back around and that fixed the problem.
Last edited by FrankTank; May 25, 2010 at 10:08 PM.
Thread Starter
Pro
Joined: Mar 2010
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From: Navarre Florida
OK guys here is the most recent news! I just talked to the mechanic and he said that he found loose grounds, but it did not fix the problem. He said that 02 sensors are fine, plugs and wires OK as well. He also said that he thought that muffler shop did a pretty good job with the headers install and he could not find anything screwed up yet. He thinks that driving with loose grounds could have possibly caused damage to the computer, and that there is a possibility of having to buy a new one . He said it would cost about 400$. Now they waiting on a GM scanning tool and asked me to leave the car for another couple days since they are very busy right now.
He is going to go over everything again and if make sure he did not miss anything simple, and then we will go from there. Also he said that it might be a good idea to take the car to a performance place that specializes in tuning cars.
I want this nightmare to be over, I am getting extremely frustrated as days go by
He is going to go over everything again and if make sure he did not miss anything simple, and then we will go from there. Also he said that it might be a good idea to take the car to a performance place that specializes in tuning cars.
I want this nightmare to be over, I am getting extremely frustrated as days go by
Last edited by ignatkor; May 27, 2010 at 02:27 PM.
Race Director
Joined: Apr 2005
Posts: 10,179
Likes: 2,306
From: Wesley Chapel, FL Las Vegas, NV
OK guys here is the most recent news! I just talked to the mechanic and he said that he found loose grounds, but it did not fix the problem. He said that 02 sensors are fine, plugs and wires OK as well. He also said that he thought that muffler shop did a pretty good job with the headers install and he could not find anything screwed up yet. He thinks that driving with loose grounds could have possibly caused damage to the computer, and that there is a possibility of having to buy a new one . He said it would cost about 400$. Now they waiting on a GM scanning tool and asked me to leave the car for another couple days since they are very busy right now.
He is going to go over everything again and if make sure he did not miss anything simple, and then we will go from there. Also he said that it might be a good idea to take the car to a performance place that specializes in tuning cars.
I want this nightmare to be over, I am getting extremely frustrated as days go by
He is going to go over everything again and if make sure he did not miss anything simple, and then we will go from there. Also he said that it might be a good idea to take the car to a performance place that specializes in tuning cars.
I want this nightmare to be over, I am getting extremely frustrated as days go by
You have never confirmed that the O2 sensors are not crossed.
FYI the Passenger side O2 plugs into the harness on the drivers side and the Drivers side O2 plugs into the harness on the passenger side.
That said, the "mechanic" could be saying everything is OK but may be ignorant of this fact.
If you take your car anywhere you MUST take it to someone that specialized in Corvettes. And If the shop you took it to is "waiting on a GM scanning tool" you have it in the wrong shop.
Thread Starter
Pro
Joined: Mar 2010
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From: Navarre Florida
Thread Starter
Pro
Joined: Mar 2010
Posts: 589
Likes: 0
From: Navarre Florida
You continue to get BAD info. Bad grounds will not waste your computer.
You have never confirmed that the O2 sensors are not crossed.
FYI the Passenger side O2 plugs into the harness on the drivers side and the Drivers side O2 plugs into the harness on the passenger side.
That said, the "mechanic" could be saying everything is OK but may be ignorant of this fact.
If you take your car anywhere you MUST take it to someone that specialized in Corvettes. And If the shop you took it to is "waiting on a GM scanning tool" you have it in the wrong shop.
You have never confirmed that the O2 sensors are not crossed.
FYI the Passenger side O2 plugs into the harness on the drivers side and the Drivers side O2 plugs into the harness on the passenger side.
That said, the "mechanic" could be saying everything is OK but may be ignorant of this fact.
If you take your car anywhere you MUST take it to someone that specialized in Corvettes. And If the shop you took it to is "waiting on a GM scanning tool" you have it in the wrong shop.
Last edited by ignatkor; May 27, 2010 at 08:34 PM.
Race Director
Joined: Apr 2005
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From: Wesley Chapel, FL Las Vegas, NV