Ok first of all, latetly my car is been RPM hunting when off the GAS, like 500-1200 while cruising & alwalys wanting to stall, I don't drive my car much but it started doing it anyways, yesterday when it died it showed these codes:

16,41,42,51

HELP!

41&42 is EST open, wtf is that!

 

16=optispark low res. pulse not found

41= ignition control circuit open


42= ignition control circuit short or ground


57= eeprom program error

if i was faced with these codes i would inspect the wiring harness,or it may just be a good old opti falure but it sounds like a bad ground or a burnt wire imo

 

This belongs in "LT1 Tech" or "Computer......"

Moving to LT1 Tech......

 

Reuploaded the tune & it went away

 

Reuploaded the tune & it went away

 

EST electronic spark somthing its the module under the coil. Thats why your car wont start i bet and or stalled. EPROM trips when that thing goes also. Im sure you know all about 16, but thats also triped when my EST went. Replace the EST you should be fine.

 

Matt, I get the 41 and 42 codes at times as well, and they have always been associated with the 16 low res opti code...

One of them is causing the other... I dunno if its my opti dying, thats causing the other codes, or the ignition control circuit dying and not sending signals to the opti...

But they do go away after I reset the PCM... And turn up a few months later, when the car will stall again...

I have no idea why, as it has only stalled a few times now, months apart, with no apparent similarities between the 2 events...

I was just figuring it was my opti, but thankfully it hasn't died for good yet

Jeff