I have a CEL 43 and my A/F shows lean all the time, so whats the most common cause for a CEL 43 on a 94 LS w/ nitrous wet and 125k miles? Injectors maybe but my aftermarket FPR is working according to my FP gauge. So that would mean anything behind the FPR is working fine right? Ive been runnign Nitrous for a few months now and it just started recently. Thanks