[2005graysti]

Hello everybody, new to the forum.
I got a 05sti not to long ago and after my breakin period I put an aps cai and reset my ecu. When I started it back up it was idleing weird which i thought was normal b/c the ecu was probably trying to adjust. Anyway I drove the car and soon afterward cel came on. i checked the sensor and all hoses and everything is fine. the car was also still idleing weird and not running like stock. Later I took off the intake and put my stock parts on. Does anybody know what caused it?

[thermobox]

do you have any other mods? go to your local auto parts store and see if they can read the code for you

[esemes]

did you have the MAF sensor mounted correctly (maybe facing 180° backwards??)

i have the APS, and helped install one for a friend (ona stock sti) and never had any issues whatsoever...


does yours have the "65" stamped on the inlet tube?? if not, then this is the older version, which was known to be potentially troublesome.. (but still usable)

ESE

[STi_BRi]

Yes, esemes is right. I have a friend who ordered an APS CAI, got it and installed it and had a CEL the first day of driving. Upon calling APS, he checked the tube and it had a 70 stamped in it which means its the 70mm one. He was told only the 65mm one would not throw a CEL. He still has the 70mm one on his car, but has since added a UTEC and a custom tune.

[2005graysti]

I have no other modifications on the car and I made sure the maf sensor was placed exactly the way it was on the stock intake. As with the intake it does not have either a 65 or 70, but the people at grd in naperville said all of the aps cai now are 65. 70 was for the old ones. I'm kind of wondering because it was a used intake that one of their techs had on their car

[esemes]

WAS IN BLACK, OR RED?

[2005graysti]

it was in red

[esemes]

okay, well it kinda eliminates the "older model " theory, but i think there still may be some of the NON-65's that were sprayed in black wrinkle paint.....

can you inspect the inside of the tube, on both ends, and look for the "65"??

if you really need, i can try to disassemble mine and snap a pic (will not be easy though)

ese

[2005graysti]

I checked everywhere inside and there arent any numbers. Dont worry about disassembling your intake, because i know it can be a little annoying. Thanks though. I'll probably just take it back to grd and return the intake or get something else.

[esemes]

okay.

it is easy to see, on the inside of the tube, about ½" from the end/lip....

if the numberrs aint there, its likely the old spec.

good luck

[davidm_sh]

First I would like to say I think APS makes some DAMN good products.

WIth that said I tried the 65 mm Red APS CAI on my 04STi with a catch can plumbed in to the car. Ran the car about 12,000 miles with the stock air-box and no CELS. Put the APS CAI on and had CELs (for lean conditions - even though the car was running just fine as verified by a wideband) every 150-200 miles. It was mostly at very slight part throttle in the low vaccuum - low boost range where I think the some extra air was sneakign past the MAF (cause of the bend in the intake where the MAF is located) causing the engine to only notice the extra air (by seeing leaner than stoich afrs) via the front semi-wideband (in the header - stock) causing the ECU to throw more fuel in thus making it think it was running lean.

I never verified this by logging the STFT and LTFT. APS was very responsive on the issue and suggested I may have had my catch can plumbing wrong (the points that go back into the turbo inlet tube). Maybe they were right but the bottom line is I took the APS CAI off and no more CELS [shrug].

I did measure about 3" or 76mm of vacuum in the turbo inlet tract before I installed the APS and then about 65mm of vacuum in the intake tract WITH the APS installed. So it did help the efficiency of the turbo and the afrs were virtually unchanged. MAYBE 0.1:1 leaner... so going from 10.6:1 to 10.7:1 as measured via wideband. So it does help and give hp but I hate CELS even though I know they are harmless... just can't stand the blinking cruise light and not being able to use my cruise control [heh].

Just for comparison sake. 76mm of vaccuum was measured in the intake tract at redline with the stock air box and air filter. 65mm of vacuum was measured with the stock intake and NO air filter. So basically the APS CAI relieved the same amount of restriction as compared to running with no air filter in the stock airbox.

[esemes]

great info, david...

how did you run their intake with the stock airbox??

im stumped!

ESE

[davidm_sh]

Originally Posted by esemes

great info, david...

how did you run their intake with the stock airbox??

im stumped!

ESE

Sorry if I was confusing but I never ran their intake with the stock air box. I was simply comparing the two and the amount of vacuum/restriction each one created.

[joflewbyu2]

Originally Posted by davidm_sh

First I would like to say I think APS makes some DAMN good products..

Just for comparison sake. 76mm of vaccuum was measured in the intake tract at redline with the stock air box and air filter. 65mm of vacuum was measured with the stock intake and NO air filter. So basically the APS CAI relieved the same amount of restriction as compared to running with no air filter in the stock airbox.

GREAT INFO. I would love to see the comparison of the stock airbox w/ the GPMOTO silencer deleat & the STI high flow filter - of course this is what i run just so i can justify the $100 i spent on performance instead of quality. the gpmoto deleat is great quality - same material as the intake scoop - not the cheap blown plastic of the resonator in which the thickness was not consistent. my resonator was paper thin in spots & super thick in others. sti air filter has metal screen, foam layer after the cotton pleats & has metal cage around all 4 corners - stock was 2 sides only

[2005graysti]

hey just to let you know, I went back to grd and they told me it was a 70mm one. so they gave me a 65mm one, so ill let you know as soon as I put the intake in. hopefully i wont see any cels. According to everybody else on this site the aps cai worked just fine.