34 and 44 would make sense as my smog pump and egr are both deleted. As for 19 what’s considered erratic? Idle is ~750. It goes up maybe to 900 then back to 750 every ~45sec
Code 19 - Engine off - No Vehicle Power (pins 37 + 57) or bad PCM VPWR
Revised 30 Mar 2019 to add computer wiring connector diagrams.
Key on, engine not running .
This is a wiring problem that is from a bad ECC power relay, bad connection, bad fuse link, bad ignition switch or a bad computer. The ECC relay is located on top of the computer under the passenger side kick panel. Pull the connector off any fuel injector and measure the voltage on the red wire: if its 12 volts or better, the ECC relay is OK. If the ECC relay is OK, pull the kick panel off and measure the voltage at computer pins 37 & 57. If it is 12 volts or more, then the computer's diagnostic firmware has taken a dump and is defective.
Computer wiring harness connector, wire side
Computer wiring harness connector, computer side
Key on, Engine running
Erratic idle during test (reset throttle & retest) - Idle Set Procedures .
See http://www.stangnet.com/mustang-forums/698148-help-me-create-surging-idle-checklist.html#post6855020 for the best way to set the mechanical base idle and cleaning procedure for the IAC/IAB.[/b][/b]