Cone Air Filter

I just installed a high flow filter to my 99 SL. Made a custom adapter to the air sensor and all seemed to go fine. Its only a 3" filter, oiled, just got it at the local autozone. However when we started the car up It had a CEL.... Ran fine though. While driving it ( I wasnt expecting a major pep increase) it almost seemed to have lost some power somewhere... However it ran fine aside from having the RPM's drop ONCE to 400 while in neutral (never repeated itsself so i thought it was a freak thing. Anyhow if anyone can tell me why the CEL went off id be more than happy to know, i dont think the sensor was damaged as the car runs fine overall. Thanks.

make sure your MAS is plugged back in securely. Also check to make sure there are no leaks where the intake meets the throttlebody.

if that checks out, go back to autozone and have them pull your CEL code. i think they do it for free and that may give you some more info on where to look or what's causing it.

Well, I checked all the seals and everything is nice and tight, no leaks. I also checked the connection to the sensor. However I still have a CEL and its not running right, If anything its gotten worse. My idle is a little choppy (however not nearly as bad as some complaints ive heard from similar problems, its only +/- bout 100rpm for me) and it just honestly just wants to sputter and stall when i take off. Ill have autozone pull the code today but does anyone have any other insight on it? If any part of the MAS/MAF got blocked off could it trip it (the main sensor didnt I know, but just in case one of those slots on the side may have been partially blocked...?)? Oiled filters I know causes problems on GM vehicles, same here? Thanks for your help.

definitely sounds like either a larger vacuum leak or a MAF problem. The MAF is pretty fragile, so it may have got damaged during the filter install. You can try unplugging it and seeing if it makes a difference. If it makes no difference or get's better, time to look for a new one.

part of the intake being blocked would hurt performance, but i dont think it would cause a CEL. Easy enough to check though. Doesnt sound like an oil filter related problem at all though. as long as you change your oil like you're supposed to and change the filter when you do, i wouldnt worry about that.

No not an oil filter, an oiled air filter. I know they will trip a CEL in most GM vehicles I was curious whether or not thats whats going on here? However most KN filters are oiled I beliee (dont quote me on that) so I couldnt really see why since so many people use FIPK's and such. Ill check that stuff here in a bit, maybe find a solution to this issue.

Oh just an update: I unplugged the sensor and the car ran like garbage, deffinately much better with it plugged in, so I assume thats checked out. And while i drive it runs pretty fine until I hit the gas, then theres a major lag followed by just not having as much get up and go as it used to.

But I cannot find any leaks or anything just from feeling... and I did open it and the 2 side parts of the MAF are a little bit covered but not much, but the middle one with the sensor is perfectly fine....

I dont have a clue whats up, any info will help. Ill get the CEL code pulled tonight and hopefully go from there. Thanks for your help so far though.

I have trouble understanding why people insist on putting a cone filter in there intake. The aftermarket world is pretty in-depth these days and when they market something they have to put fourth documentation that it is enhancing performance in some way and it can't throw any codes or imagine the squealing that would cause. Theres no telling what the air is doing in your setup, thats why a K&N or whatever kit cost $300. Testing....

I have trouble understanding why people insist on putting a cone filter in there intake. The aftermarket world is pretty in-depth these days and when they market something they have to put fourth documentation that it is enhancing performance in some way and it can't throw any codes or imagine the squealing that would cause. Theres no telling what the air is doing in your setup, thats why a K&N or whatever kit cost $300. Testing....

somewhat true. A filter is a filter. yea, some are made better, more durable, may even flow a bit better, but for the most part, i can get a cheap-o ebay filter that will flow as well as my FIPK. The FIPK is so expensive, partly because it's high quality and long lasting, partly due to testing, partly due to name brand, and partly becasue it's CARB certified, meaning it's legal in all states and wont cause you to fail on inspection, even in Cali, meaning they had to jump through alot of hoops and now the end user pays for it.

somewhat true. A filter is a filter. yea, some are made better, more durable, may even flow a bit better, but for the most part, i can get a cheap-o ebay filter that will flow as well as my FIPK. The FIPK is so expensive, partly because it's high quality and long lasting, partly due to testing, partly due to name brand, and partly becasue it's CARB certified, meaning it's legal in all states and wont cause you to fail on inspection, even in Cali, meaning they had to jump through alot of hoops and now the end user pays for it.

I agree. My setup is really no different than most other systems. Its just an adapter to the MAF and a simple filter, theres nothing to complex with it. 3sx happens to sell adapters to do the same thing, I just decided to save some money and adapt a cheaper one to work.

All this is aside, Im still curious what is causing this mystery CEL and power loss, ive yet to find any vaccume leak that i can tell at least. What about just resetting the ECU? It was suggested on 3si, however i dont see that fixing the lag my car has under acceleration now.

i would see what code it's throwing first. you can always try resatting it later, but if you reset it now and it runs fine and doesn't throw a CEL...well that would bug me and i would want to know what code it was, lol. I guess theres no real harm in it though. If it's something else, reseting the ECU shouldnt hurt anything.
I didnt have to reset mine when i put on the FIPK, but every car's a little different. that, and yours is OBDII, so alot different in this case.

Why not try putting the stock intake and everything back on and see if it improves things?

And get the code read. That will point you in the right direction better than anything else at this point.

I can almost guarantee you have leaks. You could have gotten an intake off of ebay for very cheap and it would have fit perfectly.

but even if it were getting leaks "pre-mas" would that make it run funny, or even throw a code? i kno my adapter from ebay was leakin at first, and the car still ran fine and never threw a code, since the air hadnt yet gone through the sensor...

if it is a leak, it has to be after the MAS. you should be able to run it with no filter at all without issue (other than the obvious risks).

I have a feeling you have a leak, drove around and now have sand or dirt in your vacuum lines, which WILL throw a CEL.

I agree. My setup is really no different than most other systems. Its just an adapter to the MAF and a simple filter, theres nothing to complex with it. 3sx happens to sell adapters to do the same thing, I just decided to save some money and adapt a cheaper one to work.

All this is aside, Im still curious what is causing this mystery CEL and power loss, ive yet to find any vaccume leak that i can tell at least. What about just resetting the ECU? It was suggested on 3si, however i dont see that fixing the lag my car has under acceleration now.

So the filter can flow better, does it help? What about codes? I'll pay for something that works and looks like it belongs. If you are willing to take time to make it look professional cool, I applaud your ingenuity. But prove to me your making a difference.

I would try reseting your ECU. I know when I put on my friend's filter, a couple days later it threw a CEL claiming that the plugs and wires were all bad. Well, we eventually cleared the code and the light never came back.

My guess? I'm thinking that maybe the filter allowed for "better" air flow so maybe your system needs to rescan everything!?! But that's just what I think... Since you have a '99, you should be able to scan your car easily so might as well do that. I have a hybrid so if mine threw a CEL I would be SOL!?! Which makes me wonder...what would I do to pull the code!?! LOL

i think you pull a code on a hybrid the same way you do on OBD-I :confused:

No on hybrids you have to ground the #12 pin (iirc) and then turn the switch on. The code will blink at you on the CEL on the dash.

As far as trying to save money, my entire intake cost a whopping $40. If you cant afford that go buy a Honda.

^^I'm assuming they'll be a pause between each number when blinking? How do you decipher the codes after you get 'em?

the first number will be "long" blinks. A quick pause then the second number will be faster blinks.