So i had the aem cai on my car when i bought it which is now off. Now ive herd it could cause it to run lean at times. So to my question, i know you can blow your engine if you run too lean, but my engine obviously didnt blow so are there any other effects it could have down the road? I guess my question is, since nothing happined when the intake was on, could running lean cause something that im not aware of now? Like if nothing hapined when the intake was on am i all good then, or could it of caused problems not evident as of now? Should i get a compression test? BTW i bought the car with a CAI and 3in ss catback. They were the only mods and on the car approx 40,000 miles. Thanks

 

I am thinking that you should be OK.
Sometimes a CAI can make the car run lean. This can essentially cause detonation/ping and detonation is BAD. However, even if it happens that does not mean that your engine is automatically destroyed since pinging can be "absorbed” by the engine at times. Now, if detonation did damage your engine you would probably know it right away.
So, if your engine sounds normal now, without the CAI, and you don't feel any lack of power you should be fine. If anything happened to the engine it probably happened during the time when the CAI was installed.
It's not a bad idea to do a compression test though. At leat this way you'll know if anything is wrong instead of just guessing.
Just as a side-note, I haven't actually read of anyone blowing or damaging an engine as a result of having a CAI. But most people agree that CAIs actually hurt performance on WRXs when you are relatively stock and that you will be better off sticking with the factory air box.

My $.02.

 

YA i gained performace with the stock air box, interesting. Only thing i noticed with the engine is the damn ticking, but i guess thats normal.