1999 GMC K2500 Suburban SLT 8 Cyl 5.7L
obd11 p0404 egr ckt range/performance what does it mean
runs great 99% of time
The description of the code that you’ve mention is Exhaust Gas Recirculation Circuit Range/Performance. If runs great your vehicle may have a stored trouble code, erased it simply by disconnecting the negative cable of your battery for several minutes. Try it if it works.