If an EGR valve is bad or improperly installed would this affect the transmission from shifting gears or rough shifting gears? Thanks, --tj
No. A stuck-open EGR valve usually causes a stumble at part-throttle, and possibly rough idle. A stuck-closed valve causes high emissions. In OBD-II cars a sticking or non-functional EGR valve usually sets a P04xx DTC with illuminated MIL ("Check Engine light"). Certain years and models of Hondas had bad problems with their automatic transmissions. For those vehicles there is a warranty extension. The wrong fluid will cause hard or harsh shifting.
are you sure? in my experience, if the egr or ports are clogged, the throttle flat spots. that's flow restriction, not being stuck open. personally, i don't bother with egr on my vintage vehicles since they're no longer required. replacement of the ecu [$40 from the local junkyard] with a non-egr ecu renders it inoperative and the cars drive like dreams. /and/ pass smog!
