1996 windstar surging with no trouble codes and the E flashing on scanner what might be the cause?

Question

1996 winstar , surges more at nlow rpm than hi.No trouble codes present but the e is flashing on scanner. I replaced MAF sensor, and the DPfs and engine cooant temp sensor. I used a hayes manual to check everything and itsn all good with one thing the trans range sensor is only getting 5.1 volts at the harness with it disconnected key on. Could this be the cause really i dont want to spend any more than i have all ready it has 240k its a 3.8l. The van has been awsome up to now no probs or issues. thanks in advance..

Answer 1

Surges this sound like a rolling RPM which is mainly caused by the cam position sensor, there is a TSB for this 02-22-1. This does not have to set a DTC trouble code, Surges can also be caused by vacuum leaks at the PCV valve or even the PCV hose if it is ruptured.