Ok I have a 2011 GSR with a CB exhaust as only modification. Car will run fine but sometimes get a stutter under load going up hill. If I get on the gas and push it above 4k rpms I will get a CEL that reads lean more times than not. I have replaced many fuel pump relays and as recent as this month. Car has 33 k on the clock. I am really at my wits end and am about to put stock exhaust back on a go trade car if problem can't be resolved very shortly. Please help if you can.

Thanx.

 

Im not sure what your particular problem is but im pretty sure its not the cbe..

maybe bad injectors/clogged?

 

Check fuel pressure regulator hose and fuel pump relay. Both have been known to cause lean conditions.