air filter fitment

Lima Tango

Original poster
Member
Dec 4, 2011
242
ALCON,

I purchased a new Wix air filter, and it seems like it's a little bit bigger than the old filter. It fits (tight) into the lower half of the air box, but it feels like I have to force the top down to get it on. If I screw it down tight by forcing it, the top appears to be very slightly distended. I am concerned about the right amount of air getting through if the filter is pressed tight against the box.

I left the top of the box a little loose, maybe loosened it by 3 or 4 turns of each screw. It's not throwing codes and I have Torque if there is any info that can give you that will help confirm/deny my concern. What is the correct Air Fuel Ratio? Does that vary by idle/accelerating/cruising? Is it bad to leave the top of the air box loose?

On an unrelated topic, I also installed new 41-103s (to replace the 90k stock plugs) and cleaned the TB. Even though I had cleaned the TB about 12k miles ago there was enough carbon to make me feel accomplished. Feels like it runs better now and there were no codes or any issues at all after putting it all back together :wootwoot:

Thanks for the help,

LT
 

MacMan

Member
Mar 3, 2012
194
You did get the correct # filter, 42729, right?
 

Lima Tango

Original poster
Member
Dec 4, 2011
242
MacMan said:
You did get the correct # filter, 42729, right?

Well, that's what the box says. What's weirding me out though, is the Wix pixture of this model show a blue filter. The one I got in that box (from amazon) is orange. Also, all the other wix filters I have used have fit perfect. I am suspicious that this filter in the box is not actually the Wix 42729 filter.
 

Regulator

Member
Nov 20, 2011
2,496
Is there any marking on the filter itself? I would imagine the part number / manufacturer will be stamped on the filter as well.
 

Lima Tango

Original poster
Member
Dec 4, 2011
242
Regulator said:
Is there any marking on the filter itself? I would imagine the part number / manufacturer will be stamped on the filter as well.

Had to go check. There is "Wix 42729" stamped on the side of the housing, looks like the kind of stamp someone would order to stamp their name or for "deposit only" on the back of a check. This is getting a little paranoid so I am guessing its probably what its supposed to be, just disappointed in the fit.

Btw - my intake air temp is about +20 degrees F, and the commanded AFR is 14.6 unless I am accelerating when it drops as low as 12.6. The fuel bank trim varies mostly between +-2% with the occasional +7%.
 

pennywise

Member
Mar 28, 2012
46
Your AFR is right on. 12.2-14.6 is where it's supposed to be depending on the load on the engine. There isn't much room inside the box for the filter in the first place. If it doesn't fit right I would replace it. Maybe try a differnent vendor or a different site.
 

MacMan

Member
Mar 3, 2012
194
Lima Tango said:
....What's weirding me out though, is the Wix pixture of this model show a blue filter. The one I got in that box (from amazon) is orange.....
You are correct on the correct Wix color....it's supposed to be blue.
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
Send an email to Wix.
Ask if they know about any counterfeit filters with the orange color.

Also, depending on what you hear from Wix, contact Amazon and tell them they are selling counterfeit parts.
You should get all your money back. Including s&h.
 

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