Originally Posted by tommyboy8072002
Ok 1406 is a Egr valve pintle position circuit. Will this cause pinging? I Also found a bad Ground wire. but I don't know if that would cause this truck to run like junk.
Yes a failed EGR will cause pinging. The injection is programmed to deliver the correct mixture for the air bearing oxygen present in the intake system while the EGR is also putting in an amount of inert exhaust gasses. If the EGR is not putting the inert exhaust gasses into the intake that space becomes occupied by air with oxygen. The computer has no way to know this so it continues to fuel as if there is a mixture of fresh oxygen bearing air and inert exahust gas rather that a lot more fresh air and no exhaust gasses. This causes the mixture to fall lean which will result in pinging and back firing.