Hey guys, I've been having problems with my 2011 Evo X. So my AFR keeps jumping between 11 and 18. When it goes to 18, I can feel a huge loss in power like suddenly I'm pulling a trailer with another car in it. It'll be like that for like a second or two until the afr goes to the other side. Also, before I can use my AC and it wont affect my idle at all, then recently when I turn on the AC the tach will keep jumping back and forth between 1k and 500 and sometimes will stall the engine. Some days it'll do that and some days I can turn on the AC and its fine.

Mods are:

GSC S2 Cams and springs
FIC 1100
AEM 340 Fuel Pump
Synapse BOV
K&N hi flow intake
TopSpeed Test Pipe + Catback
3 port EBCS

Any help is appreciated!

 

It may be your fuel pump relay when they die the car runs super lean. You should replace yours immediately and stop driving the car.

 

You know what? You might be right, I still got the stock one if I remember correctly (Just bought this car recently). Ill go check and swap it for now and see if it improves.

 

I swap the relay a few times with a different relay and the problem still persists.

 

AC affects my idle and I'm stock so that's probably not the issue. I would think its the tune or fuel pressure related .

 

Who tuned your car, when was it tuned? Did it ever run right as it sits? These are the answers people need to better assist you.

 

You check your fpr vacuum to make sure it didnt pop off?