Can bad EGR cause trnsmission problems?
I have the MH listed in my signature i.e. Chevy 454 P series with I believe the 4L80E transmission. Recently experienced problem with not shifting into overdrive and intermittent Check Engine light. ...
Forum Discussion
ScottG wrote:allbrandauto wrote:
A egr valve that has a vacuum leak will give you rough idle when you go down the road the egr valve opens up letting exhust into the intake to get rid of a gas called nox don't think this is your problem again cat. converter can cause this but you would also have no power is it not going into high gear or is the torque converter not locking up if its the torque converter not locking up could be brake light switch
It wont always give a rough idle.
Vacuum is only applied under certain throttle conditions (not at idle) and with the throttle closed, the engine will idle perfectly unless the EGR valve is stuck open - that is the only time it will cause a rough idle and that failure mode is rare. The usual failure mode of an EGR is that the vacuum diaghram gets ruptured. Then the vavle doesn't respond properly. Then at intermediate throttle positions, you will have a vacuum leak because the ECM is trying to apply vacuum to it and it's leaking.
