Ok, I have a few questions about cold air intakes. My S, which I purchased last saturday (used) came with an AEM CAI. Its not a part that I would have purchased on my own, and I'm not yet sure whether I want to leave it in or not.

I have a few questions about it:

What does a CAI do/how does it work? I understand that it increases torque/hp, but, simply, how?

The guy that I purchased the car from mentioned that the CAI is missing a sensor. He showed me where it plugs in (there is an open plug that is very obvious) and he said its supposed to fit into a hole in the CAI. Does this sound correct? If so, can anyone give me a part number or anything for it? I have a check engine light on and he said that this missing sensor is the cause. He was very up front about the whole deal and I trusted him on it. Can anyone help me with this?

Does anyone have a pic of their engine bay with a CAI installed? I'd like to see how mine looks compared to anyone else's to see if it looks right. Thanks!

 

I have CAI and my engine light is not on.

 

There should be no sensor in the CAI. However, the solenoid valve for the exhaust air injection is bolted to a bracket on the underside of the top tube. This is an emissions control device, so it won't hurt the car if that's what's missing, although I don't know why it would be missing.

The CAI makes its power two ways. The first is by helping the engine get cooler air, more of the time. But a bigger contribution comes from improved flow vs. the restrictive stock box and corrugated rubber tubing. Additionally, the longer piping creates some beneficial resonances that really boost torque in the low rpm range (around 3500 rpm).

The only problem with CAIs is cleaning the filter and if you live in a rainy climate you need to be careful driving through standing water.

UL

 

[QUOTE]Originally posted by ultimate lurker
[B]
The CAI makes its power two ways.

 

Great. It sounds like the guy that I bought the car from may have installed it wrong. I'll have to get together with someone and have them look at it.

 

My guess would be he didn't have all of the correct tubing with him and merely plugged up one of the tube holes...no sensor goes there, but probably a connection to the air pump or some such item.

 

Yeah, I noticed that too. There is one tube hole that has been taped over, and then he said that he drilled a hole in the CAI for the sensor, and there is a wiring harness for the sensor that is quite obvious too. I think he may have done a reasonably crappy job with the install. I'll have to decide if I want to keep it or if I want to pull it and put the stock box back in.

I really want to take care of the check engine light though.

 

[QUOTE]Originally posted by munckee
[B]There is one tube hole that has been taped over, and then he said that he drilled a hole in the CAI for the sensor, and there is a wiring harness for the sensor that is quite obvious too.

 

BTW here is a pic of my Injen, although I am not sure you can see what you are looking for.

 

I have an AEM on mine. The most obvious difference is the sounds it makes at 6k rpm. Also a moderate improvement in throttle response especially on hotter days. There also IMO seems to be a substantial torque increase at lower RPM's but I have no proof of that. As to hydro-locking my engine I have no concerns.