Upgraded panel filters and lean condition

In a couple threads, I've seen guys from TDC swear that upgraded panel filters cause our engines to run lean. I respect their abilities but, let's face it, their business is selling maps for modifications like panel filters.

 

Has anybody else seen a lean condition caused by a panel filter?

It didn't happen on the '05's, that's a fact.

I purchased an AP with custom TDC maps from a former member here. One of those TDC maps is tuned for a panel filter and it "seems" to run better than the others. Butt dyno is my only reference so take it FWIW...

Dunno... some of the newer GT's have been reported to run somewhat lean on stock tunes to begin with.

One member that has an AVO panel filter, it did run leaner after initial ecu reset. However, AFR learning adjusted itself so that it probably ran normally afterwards.

 

It was a 2005 5MT.

I dont really see how it is going to make it run leaner. Lean condition by aftermarket intakes is caused by the housing around the MAF sensor being different than stock. That causes the MAF sensor to read incorrectly. Putting in a filter should not make any difference.

 

I have a K&N filter in mine, and have datalogged several different times with no problems.

K&N panel filter here, no problems, running the exact same as before I put it in.

I have the AVO filter and my car runs fine. 2005 gt 5MT

Have you guys checked your AFR Learning A, B, C, and D.

 

I don't own the AVO panel but one person I know does have it. Upon initial ecu reset, it leaned out and it did knock.

 

However, after driving around a bit, the AFR learning adjusted itself and everything was back to normal.

 

If you add turbulence ahead of the MAF sensor, it will affect it.

 

I know for a fact that if you leave the airbox door improperly latched, it will affect the MAF sensor. Clearly that means turbulence ahead of the MAF sensor affects the MAF sensor. Jazzmyt plus another person has already experienced this CEL first hand.

 

http://legacygt.com/forums/showthread.php?t=62020

05 OBXT w/ AVO filter for over 15k miles, not 1 problem.

I installed an AVO panel filter about two weeks ago. My average gas mileage has since dropped nearly 2 mpg. I suspect the ECU is compensating for increased air flow by burning more gas.

Most would not know of any problems unless you have a wideband O2 in place. I do also agree in theory it should run the same, but as stated added turbulance could impact the MAF's readings.

I'm not seeing anyone post up their AFR learning A, B, C, D numbers.

 

BTW, I heard that cleaning a really dirty air filter will also change your scaling.

BTW, I heard that cleaning a really dirty air filter will also change your scaling.

Yep about a .7 point difference.....

I was on the dyno all weekend, and actually had a chance to test out this theory on an 08 STi (which shares an identical airbox design with our cars). Made a couple pulls with the stock air filter, then a couple pulls with a K&N drop-in filter. There was no appreciable difference in AFR.

Pretty sure my mileage has dropped with the K&N panel filter, although winter driving may be affecting it also.

It didn't happen on the '05's, that's a fact.

 

 

im over 60k miles with the AVO filters and A O K

^^^

Have you check your long term fuel trims Erwin? You wouldn't know if you were running lean unless you have a wideband or have checked the fuel trims.

I understand that changing the airflow before the MAF can affect it. Putting in a filter is not going to do that. You are not changing the airflow into or out of the airbox, so the only thing that is going to change is the ease of the air to flow through the filter.

 

Like I said before, I have datalogged several different times and there is no difference in AFR's and no knock, even just after a reset. Now, as most know, each car is different, so it could be that another vehicle is getting a different reading than mine.

 

I just know that a K&N filter on my car is fine.

 

Like I said before, I have datalogged several different times and there is no difference in AFR's and no knock, even just after a reset. Now, as most know, each car is different, so it could be that another vehicle is getting a different reading than mine.

 

I just know that a K&N filter on my car is fine.

Datalogging will not pick up any important AFR infomation outside of closed loop, you would need a wideband or to check long term fuel trims. You may not knock at all, but it still doesn't mean it isn't running leaner than the target AFR's.

 

As MickeyD stated, everyone keeps saying they are fine but no one is listing there long term fuel trims which would indicate if you are truely running lean or not.

^^^

Have you check your long term fuel trims Erwin? You wouldn't know if you were running lean unless you have a wideband or have checked the fuel trims.

 

hmmm no i havent. i was gonna re-dyno before and after when i get that boostjunkie EL header in. i'll have the Pauls check it then.

 

btw, when did you get a G35 mang!

hmmm no i havent. i was gonna re-dyno before and after when i get that boostjunkie EL header in. i'll have the Pauls check it then.

 

btw, when did you get a G35 mang!

I've had it for about 3 months now its pretty pimped for the wifey with 20's and all. Looking to eventually go for a nice cheap staggered set, nothing wild just probally 9.5" in the back for a deep lip.

Datalogging will not pick up any important AFR infomation outside of closed loop, you would need a wideband or to check long term fuel trims. You may not knock at all, but it still doesn't mean it isn't running leaner than the target AFR's.

 

As MickeyD stated, everyone keeps saying they are fine but no one is listing there long term fuel trims which would indicate if you are truely running lean or not.

 

 

I get what you are saying now. I havent seen any knock, and its obviously not running lean to a point where it would be unsafe, since its not pulling timing at all. I can see how it may run a bit leaner than stock, but I dont think it would ever get near an unsafe level........not that you stated it would.