i have a 1999 nissan maxima.it runs good.it has a problem that comes and go.the check engine light comes on.the error in the computer says: egr valve flow mulfunction.
the egr valve was changed.nissan dealer says the intake plenum is clogged with carbon and need to be cleaned.is this make sense?
The clogged plenum could very well be correct. The bigger question is why whoever changed the EGR valve did not inspect and do this at the same time as the EGR replacement.
It’s quite possible clogged passageways was the only problem to begin with.