It looks like this EEC based joke caught a few people :). It was basically saying if you add a resistor to the ground strap, it would trigger some sort of hidden “performance” mode. Below are some helpful links that may not provide any secret programming modes but will give you a great idea on how the EFI system works on our foxes. No joke, the little old EEC-IV is actually very easy to live with.
- All EEC-IV Sensors and how to correctly adjust idle and TPS.
- SMOG system explained – it really isn’t as bad as you think.
- EEC Trouble Codes and how to read them.