Right after I got my 2013 Eco I went out and put a 4 inch CB Flowmaster exhaust on it. I have always ran K&N CAI in my trucks so after the exhaust was installed I had one put on. My question is.... Should I replace the K&N and put the stock filter back on? It seems like I have too much air flow with the K&N CAI and the 4 inch exhaust setup. Could there be too little restriction? Just wondering if I switched back that if it would help the performance and or MPGs. Thanks in advance for any input.