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Old 04-07-2002, 10:48 AM   #1
Scooby Newbie
Member#: 17091
Join Date: Apr 2002
Location: Hooksett, NH
02 ts

Default CAI safety?

I just installed a CAI on my 02 2.5 ts. I've been searching through the archives reading peoples concerns with MAF failures, knock, detonation, lean and rich conditions, etc. etc. Should I be concerned with these? I retained stock filter and housing. Some threads say to install a different MAF, kandN filter to help with lean state, don't install filter will mess up MAF, so on and so forth. Are these concerns legitimate, do I need to be worried? Will I have any warning signs or indications of failure(check engine light etc.) There is so many contrasting threads, who is right and who is wrong? Or is it just a matter of luck whether or not you'll have a problem. Thanks for your advice.
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Old 04-07-2002, 12:43 PM   #2
Scooby Specialist
Member#: 827
Join Date: Jan 2000
Chapter/Region: MAIC
Location: Bel Air, MD,USA
99 2.5rs,BDP,
02 WRX, 09 Legacy


The MY99 rs is the only one with a maf so I dont think you have to worry about that, and I think the maf is what caused teh car to run lean also. I have an intake on my 99 with no problems. So I wouldn't worry about it.

Anthony C
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Old 04-07-2002, 02:19 PM   #3
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Member#: 2683
Join Date: Oct 2000
Chapter/Region: South East
Location: Atlanta, GA
2011 STi 5-Door


The MY98 and MY99 RS had MAF sensors. The 98 used a hot wire and the 99 used a film. The film in the 99 was a fragile part, and intakes could break it. Since 2000, the RS has used a MAP sensor that's much more sturdy, although perhaps slightly less accurate. You should have no problems with an intake.

Ross N.
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Old 04-07-2002, 02:48 PM   #4
Scooby Specialist
Member#: 13908
Join Date: Jan 2002
Location: Irving, TX
2002 WRX Sedan
296 whp


I've always heard horror stories about CAI sucking up water...My vortech supercharged mustang was designed to pick up air from the fender and it died on me after hitting a big puddle. Until I hear why our stock intake is a big restriction I'll be sticking with it.
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Old 04-08-2002, 01:33 AM   #5
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Member#: 2272
Join Date: Sep 2000
Chapter/Region: BAIC
Location: Fire Caves
2016 Commodore SS
Heron White


matty you have a MAP not a MAF, so any MAF things you hear about dont apply to you.
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Old 04-08-2002, 09:38 AM   #6
Mr. Rogers
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Member#: 17028
Join Date: Mar 2002
Location: Patiently Waiting for an 05 Legacy STI.
2002 2.5 TS wagon


Matty : Your 02 uses a different sensor I belive that the 99's. The only fear I would have is hydrolock as the i-clubber with the mustang pointed out. This is a legit concern, i heard the cobb tuning CAI has a bypass to prevent this. I know AEM makes one and I had one on my last car but I don't recommend AEM for a subie.
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Old 04-08-2002, 02:43 PM   #7
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Member#: 1132
Join Date: Mar 2000
Chapter/Region: BAIC
Location: San Francisco, CA

Email I got from [email protected] before I bought one from them......

The intake for the RS is the result of many weeks of dyno testing. It uses
a unique in-line filter and carefully selected piping to maximize top end
power, as well as keeping the mid and low end torque that many RS owners
demand, something that most intakes cannot do. It sources air from high up
in the fender so that you do not have to worry about inhaling water, while
still getting the benefits of sourcing cooler, denser air. All of the stock
sensors remain fully functional and it is well within their operating range.
This is a very important design feature that not all intake into account.
So in other words, no fuel computer is needed. The reports you may have
heard are the result of an improperly designed intake.

Do not hesitate to ask if you have any other questions.

Cobb Tuning
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Old 04-08-2002, 02:54 PM   #8
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Member#: 6010
Join Date: Apr 2001
Location: Syracuse, NY

a friend in a 02 wrx had installed a diy cai and is now haveing problems like a rough idle and stalling and cel I told him to look over the cai for leaks but he says it fine... so i dont know maybe cai might do some damage to the car
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Old 04-08-2002, 04:38 PM   #9
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Member#: 7131
Join Date: Jun 2001
Chapter/Region: TXIC
Location: Houston - Downtown Julie Brown
2015 Outback - Croc
Dundee Edition Ice Silver


Key word is WRX... We are talking about a 2.5TS. The ej25 responds well to intakes, and makes a considerable increase in power.
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Old 04-08-2002, 06:57 PM   #10
Richard L.
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Member#: 8465
Join Date: Jul 2001
Chapter/Region: NWIC
Location: Puget Sound, WA
'00 2.5RS Coupe, AW
'93 GMC Typhoon AWD


I don't think the Cobb CAI has a bypass to prevent sucking water. A local owner hydrolocked his motor, which had the Cobb CAI, while driving through ankle deep puddles of water.
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Old 04-08-2002, 10:57 PM   #11
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Member#: 16868
Join Date: Mar 2002
Location: Greensboro, NC
1999 2.5 RS / YZF R1
WR Blue / Red&White


Maybe the AEM bypass valve could be used with one of the more popular intakes, like the Cobb, etc?? You can get them seperately for like $40 or $45. Any opinions?
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Old 04-09-2002, 03:56 PM   #12
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Member#: 9213
Join Date: Aug 2001
Location: My grandma was 6' 6"
2000 RS


If you hit water hard enough, ANY intake can suck up water.
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Old 04-09-2002, 04:24 PM   #13
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Member#: 9015
Join Date: Aug 2001
Location: one boring place, WA
2002 Impreza 2.5RS
Platinum Silver Metallic


Originally posted by mrbillydee
Maybe the AEM bypass valve could be used with one of the more popular intakes, like the Cobb, etc?? You can get them seperately for like $40 or $45. Any opinions?
The AEM bypass valve only does it's thing when the opening in the intake pipe is completely submerged. The valves on the bypass valve operate on pressure differences. Pressure differences large enough to cause the valves to open only occur when the intake opening is submerged.

It a good investment for honda/acura intakes, because those put the opening down really close to the ground to get the cold air. In the case of the cobb and other intakes that go into the fender, that's some deep water to get the opening submerged.

I read somewhere that you can hydrolock your car by ingesting something like 3 table spoons of water or something like that at once.

I did some research on this when I was deciding on what intake to get (I ended up getting the .PDM ), and came to the conclusion that it'd be a waste of $40
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