Situation has arrived...
Thread Starter
Instructor
Joined: Feb 2004
Posts: 159
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Situation has arrived...
I took my car to the dealer for clutch install, ac check/repair, and an alignment. I have headers, big cam, heads, the works done to the car...anyways, when I went to get the car and start it, it threw a million codes.
Did a few start cycles, and all the codes went away but one code keeps coming back. It is the P0300 code, which is a misfire code. The car was tuned and running excellent before it ever went in there.
I never had the misfire code before I went there, but now I do. I am wondering what could have been done to cause this.....Maybe a leaky header since they did have to come off for the clutch install....I dont know....
It also only really throws this code at an idle or just crusing around at low speed and rpms.
Any ideas from anyone?
Thanks again in advanced!
Did a few start cycles, and all the codes went away but one code keeps coming back. It is the P0300 code, which is a misfire code. The car was tuned and running excellent before it ever went in there.
I never had the misfire code before I went there, but now I do. I am wondering what could have been done to cause this.....Maybe a leaky header since they did have to come off for the clutch install....I dont know....
It also only really throws this code at an idle or just crusing around at low speed and rpms.
Any ideas from anyone?
Thanks again in advanced!
Safety Car
Joined: Aug 2000
Posts: 4,537
Likes: 84
From: St. Joseph MO
Cruise-In III Veteran
Cruise-In IV Veteran
Re: Situation has arrived... (ilcorvettegiallo)
Check the ground wire, back of drivers cylinder head. Check the coil pack connectors. Have another set of spark plug wires to try in the mean time?
Le Mans Master
Joined: Jul 2002
Posts: 7,370
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From: Slave to the evil empire
Cruise-In V Veteran
St. Jude Donor '04
Re: Situation has arrived... (ilcorvettegiallo)
You need to let the person who did the clutch install fix this because there is no doubt in my mind they caused it, the first thing that needs to happen is to hook up a scanner and find out which cylinder or cylinders are misfiring. 
Melting Slicks
Joined: Oct 2002
Posts: 2,855
Likes: 0
Re: Situation has arrived... (NV MY C5)
particullarly if you have an over lapping cam the code must be turned off with ls1edit--I just find it odd that it started after a clutch install and you had no probs before--did they touch the pcm for any reason--they disconnected the battery for the install i'm sure, did booting the PCM back up after the reconnect cause it to recognize the code---if you don't have a cam then they did something--
Le Mans Master
Joined: Nov 2002
Posts: 7,179
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From: Charlotte, NC
Re: Situation has arrived... (NEPTUNEBILL)
if you don't have a cam then they did something--
-Rick
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Burning Brakes
Joined: Aug 2000
Posts: 889
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From: DFW tx
Re: Situation has arrived... (jrose7004)
After I did heads/cam, everything was fine at first, then I started getting misfires. Turns out my plug wires were too close to the headers and even though they did not appear to be damaged, they were toast on 2 cylinders. Replaced the MSD wires with stock wires/stock heat shields and everything has been fine for a year.
Instructor
Joined: Oct 2001
Posts: 249
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From: Mesa AZ
Re: Situation has arrived... (Jeff Jeff)
Did you have any aftermarket programming in the car with the cam? Most of the time, tuners de-sensitize the knock parameters at idle for a big cam. If the dealer flashed the computer with a new update as a "courtesy" for you, you may have completely stock programming in there again.
Mike
Mike
Le Mans Master
Joined: Dec 2003
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From: Atlanta metro Ga.
Re: Situation has arrived... (mike@xtreme)
Did you have any aftermarket programming in the car with the cam? Most of the time, tuners de-sensitize the knock parameters at idle for a big cam. If the dealer flashed the computer with a new update as a "courtesy" for you, you may have completely stock programming in there again.
Mike
Mike
I would definitely check to see if they flashed the PCM as a result of a recall, i.e. CL, etc. I hope (for your sake) they did not, unless you can restore it. Good luck.
Le Mans Master
Joined: Aug 2000
Posts: 5,294
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From: Suffolk, Long Island NY
Re: Situation has arrived... (Dan_the_C5_Man)
Did you have any aftermarket programming in the car with the cam? Most of the time, tuners de-sensitize the knock parameters at idle for a big cam. If the dealer flashed the computer with a new update as a "courtesy" for you, you may have completely stock programming in there again.
Mike
Ahh shoot, you beat me to it!!
I would definitely check to see if they flashed the PCM as a result of a recall, i.e. CL, etc. I hope (for your sake) they did not, unless you can restore it. Good luck.
Mike
Ahh shoot, you beat me to it!!
I would definitely check to see if they flashed the PCM as a result of a recall, i.e. CL, etc. I hope (for your sake) they did not, unless you can restore it. Good luck.
Any big cam will cause that code, most tuners will delete it for you without telling you.
Thread Starter
Instructor
Joined: Feb 2004
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Re: Situation has arrived... (Face)
I went back today and they said 3 of the cylinders were misfiring every once in a great while. They said 2 of the spark plugs (NGKs) were fouled out, and that 1 of the spark plugs wires were not sealing right. I find it kind of weird that it never did it before, but now it is.
I talked with Lou at LGM, and he said if they flashed the pcm to stock, the car would not be running. I have the G5X-3 cam on a 110 lsa, along with the FAST 90 mm intake and the LGM 90 mm TB.
The car has less than 10k miles on it, I can not see how the wires are not sealing right/disfunctional.
Some of the wire boots do touch the headers, but I can not seem to keep them from touching.
I wish I could get the car back to LGM in Texas, because the car is still not idling right from the latest tune in Detroit, MI.
[Modified by ilcorvettegiallo, 5:46 PM 6/30/2004]
I talked with Lou at LGM, and he said if they flashed the pcm to stock, the car would not be running. I have the G5X-3 cam on a 110 lsa, along with the FAST 90 mm intake and the LGM 90 mm TB.
The car has less than 10k miles on it, I can not see how the wires are not sealing right/disfunctional.
Some of the wire boots do touch the headers, but I can not seem to keep them from touching.
I wish I could get the car back to LGM in Texas, because the car is still not idling right from the latest tune in Detroit, MI.
[Modified by ilcorvettegiallo, 5:46 PM 6/30/2004]
Le Mans Master
Joined: Aug 2000
Posts: 5,294
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From: Suffolk, Long Island NY
Re: Situation has arrived... (ilcorvettegiallo)
You need these: http://www.designengineering.com/pro...sp?m=sp&pid=22
They're a must if you have headers.
They're a must if you have headers.