I know typically you don't try and pull codes while the engine is running and even for live data you plug the scanner in before you start the car. That said, The previous owner of the vehicle apparently has wired ECU power to the ignition cylinder and I'm not exactly comfortable enough with wiring to go hunting for that little gremlin to undo it. So I'm wondering how dangerous it is to shove a paperclip in the OBD port with the engine running? Every time I turn off the engine to check the code it just clears the ECU. Opinions?

 

Won't work, with a running engine the SES/CEL is used to indicate lean, rich, or open loop. Only at key-on, engine-off does the ECM blink the codes.

RBob.

 

Yup, sounds like it's time to find and undo the PO's "improvements".

 

Yea something was telling me that's my only option. Not the only "improvement" that needs to be undone...like the T junction in the exhaust...but anyway thanks guys I appreciate it