If you fit a full
TBE system to a 02 Bug eye, the
ecu will detect irregular signals from the two O2 sensors on the exhaust.
The reason is that there is one o2 sensor before the cat on the down pipe and another o2 sensor after the cat. there is also another cat after the second o2 sensor and before the first on the up-pipe.
The
ecu expects to see differing signals from these two o2 sensors.
When you get a full 3inch
TBE the cat on the down pipe is usually removed, so the two o2 sensors will end up detecting the same levels. This throws out the
ECU which is expecting differing signals and causes it to go into limp mode.
Limp mode reduces your boost to default wastegate actuator setting and retards the ignition timing. The result is a very sluggish car.
You will need at minimum a re-flash of your stock
ECU in order to make the most of your new
TBE system.
You can still drive around on limp mode for a little while, but it is not recommended.