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After Headers, Runs Like Crap

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Old Aug 7, 2014 | 05:56 PM
  #1  
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Default After Headers, Runs Like Crap

Hey all,

Just some starting info:
02 Camaro z28
AIR removed
LT Headers
ORY
NO rear o2's (not tuned out just not pluged in)
Stock Everything Else

I just recently put LT's on, and while i had it apart, changed plugs & wires.
Took the car out for the first time, and it runs like crap.

It hesitates, surges, bogs, etc. Ran great before all this.

Had no issues prior.

Here's what im thinking, i am guessing bad o2. and would like to know what readings i should be getting.
When I run my scan tool, i can view current data and see o2 voltages. The data is as follows at just idle, no throttle change:
o2s11 .1-1
o2s12 .445 steady (bc its not plugged in???)
o2s21 .445 steady
o2s22 .445 steady (bc its not plugged in???)

so im wondering, at idle, is the correct reading the one that changes or the one that is steady? I would guess the one that moves, which would indicate it is trying to adjust for AFR. but im not sure.

I also am getting codes for a random misfire p0300

Looking to get my car back to being responsive and running well again.

Thanks in advance for any help.
Grady
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Old Aug 7, 2014 | 07:12 PM
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Originally Posted by MaroonMonsterLS1
Hey all,

Just some starting info:
02 Camaro z28
AIR removed
LT Headers
ORY
NO rear o2's (not tuned out just not pluged in)
Stock Everything Else

Grady
This is your main problem right here. Get those working and you'll be a lot better off.

Once that's done, you might need a dyno tune.
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Old Aug 7, 2014 | 10:26 PM
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Get a mail order tune.
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Old Aug 8, 2014 | 12:22 AM
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Looks like you've got a front O2 sensor that's either bad or maybe it 's not fully plugged in.
FYI, I've got a set of O2 sims in excellent condition if you're interested, or get the rear O2s tuned out.
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Old Aug 8, 2014 | 08:38 PM
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Does the car run ok when it's cold and still in closed loop and then start running badly once it goes into open loop? O2 readings shouldn't be steady - they should show some switching - and vary according from idle to easy driving to WOT.

Make sure you don't have an O2 wire sitting on a header tube and shorting out.
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Old Aug 8, 2014 | 09:06 PM
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rear 02s being unplugged should not have any effect on how it runs, they are there strictly for monitoring catalyst operation. Looking at your data reading it looks like your driver side 02 sensor is not working correctly, it should be switching like the passenger side is. I would also check all your plug wires to make sure they arent melted to the header. I had one melt one time and cause a misfire and only set a P0300 code.
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Old Aug 8, 2014 | 10:30 PM
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This is your main problem right here. Get those working and you'll be a lot better off.
His rear o2 sensors being unplugged have absolutely nothing to do with his car running the way it is now. And his car will run exactly as shitty as it does now even if he plugs those back in.

His issue is with the front o2 sensor on the passenger side.
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Old Aug 8, 2014 | 10:46 PM
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What's plugs did you use and at what gap? I put in tr55s at stock gap .59 in my ss and my friends ss..Both had misfires and ran like ****, misfiring, popping, low power etc..pulled the plugs and could see it werent getting a complete burn around around the ring on the plug..we both switched to ngk tr5s which is the smaller gap but exact same plug at .40..Both cars ran like new again..One was a long tube and bolt on car and my car has a torquer v2..hope this helps goodluck

Last edited by jaejae; Aug 9, 2014 at 07:51 AM.
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Old Aug 8, 2014 | 10:53 PM
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Like stated make sure o2 is plugged in all the way, and make sure all the plug wires are on.

Reset the PCM and see if that clears up the misfire code worked for me last week.

I didn't have o2 problems but I should of run the old o2s for a day or two and let all the crap burn off the new headers. Maybe the o2 didn't like that and f'd one up???

Resetting the PCM cleared a bunch of things going on after my install that's all I know from experience.
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Old Aug 8, 2014 | 11:53 PM
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I just thought of something maybe you got a bad o2 wiring extension.
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Old Aug 9, 2014 | 07:55 AM
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Stop messing with your oxygen sensors. Find the cracked plug(s) or improperly connected spark plug wires.
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Old Aug 9, 2014 | 08:21 AM
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You need tune period. Hell my car ran like **** when i had LT Headers installed. Fix the O2 sensors and get a tune it will run better after that.
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