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Discussion Starter #1
I've noticed that since I installed the Crawford plenum, I get a strong odor of exhaust fumes, almost as if it was too rich. Does anyone else have this problem? Do I have to torque down the plenum to a certain point? I tightened it pretty hard w/o breaking anything. I usually smell this when sitting and idling at a light or stop. Never when I drive. Let me know! Thanks!
 

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its probably the combination with your plenum and test pipes.. i had strong exhaust smell with my test pipes and intake, but its not as strong with just test pipes.
 

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[/quote]
I was going to type that the new plenum leaned out my mix a little...not very helpful so I ditched it.
 

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Discussion Starter #6
Thanks, guys. I really like my combo, even though it feels like I've lost some torque. I'll keep it for now, but **** that smell is foul. I almost think I have a leak in the system, but I don't get a CEL which is good.
 

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It's funny how a post like this comes up right after I fix a similar problem on my Z.

DAVE...

Not sure if you are experiencing the same issue I had, but over time I noticed a strong smell of gas/fumes. First, try this. Take a short drive making a few "spirited" accelerations. During this, make sure your windows are up and your AC & interior ventilation is off. Just before you return home, cut the AC on. Does the smell get stronger?

This was the case with mine and I was able to quickly determine the smell was coming from the engine bay, not the exhaust (because of where the AC inlet vents are located).

What I found was that I had developed a very small fuel leak somewhere on the passenger side near the rear of the plenum. In my case, I had a small amount of moisture and dust gathering on the valve cover just behind the #6 coil pack. Despite the evidence of a leak, I could not determine where the leak was coming from.

Ultimately, I took my plenum completely off and removed the hard fuel line that leads to the fuel rails. I replaced the O-rings in the fuel line, used stronger clamps on the rubber hoses attaching to the hard fuel lines, and replaced my lower and upper plenum gaskets. The lower and upper plenum are to be attached using a specific torque sequence tightening bolts to around 13 N*m. I was surprised how light this setting felt. So it is very possible you have overtightening on the plenum.

This process solved my problem, though I cannot say which specific fix took care of the culprit. All total, I think I spent about $15 in parts and a day in the garage taking my time to address the issue.

If the AC trick doesn't make the smell in your car increase, then most likely it is your mods causing your car to run a little richer and is perfectly normal.
 

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Discussion Starter #8
Thanks, Andy. I'll look into this soon. I am pretty sure it's coming from the engine bay. I'm not looking forward to taking it all apart again, but I have noticed that my gas mileage is not that good.

Where did you order the o-rings and clamps from?
 

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If you want to try to retorque those bolts, I have access to a few torque wrenches you can set to the proper ft/lbs or N*m.
 

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Discussion Starter #10
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That would be awesome, Colin! Maybe you can bring it to my house next week for the Z meet! I don't have any and am too cheap or lazy to go out and get one right now. I need to spend time detailing her for the big road trip.
 

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Discussion Starter #11
Andy, I tried your test and got no fumes in the Z. I suppose that's a good thing! So now all I have to do is live with the smell at idle... :shiftdrive: That's okay, anything in the name of power and sound.
 
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