I have two issues with my evo, I hope you guys can help me out...

When I have my A/C on I hear a very loud rattling/clanking noise. I think its my exhaust hitting the oil pan but not 100% sure. Also when the A/C is on the RPM's at idle are very low sometimes down to 400 RPM's. The RPM's will then intermittently bounce up to 1200 RPM's at idle, then back to the normal 850 RPM's or so. There is no order to this just randomly goes through these cycles. This all happens when the A/C is on. The rattling noise is not present when the A/C is off

However I have also noticed when the A/C is off, and when I am coming to a stop and idling, the RPM's will drop to the normal 850 and then bounce up to around 1200. This problem might tie into my next issue... When I give full throttle I feel a power cut or boost cut. I am not sure what is going on, but I know there is not full power. It seems to happen in all gears although first gear has the least issues. I think it happens at any RPM where there is boost.

Let me know what you guys think.

 

mods on the car? specifically does it have cams? alot of times cams will cause this and or a combination of the bov being vented to atmosphere when it shouldnt be.

 

^^^ this. Or could also need a bit of a tune adjustment in the idle settings. Also a boost leak can sometimes mess with idle

 

Full megan racing exhaust
ACT 6 Puck Sprung Clutch/gruppe-s Flywheel
Transfer Case Rebuild by Sheptrans

No tune

 

with no A/C on the car will intermittently rise to about 1200 RPM's at idle. I want to say while it is doing this, I am losing the power but again I am not 100% sure.

Also the A/C will sometimes blow hot air...