Bad mpg ? Causes

[mani12354]

try checking the inlet manifold  cable which runs at the back of it to the ecu, and also give ur throttle body a clean!

[thai-wronghorse]

Fuel gauges are notoriously ghey on mk3's due to the idiotic fuel tank design.

[dom]

Fuel gauges are notoriously ghey on mk3's due to the idiotic fuel tank design.

And a poorly designed sender

[spudboy6]

try checking the inlet manifold  cable which runs at the back of it to the ecu, and also give ur throttle body a clean!

I've found some fault codes

Co2 sensor -changed
Idle speed sensor ?
Idle speed limit exceeded i think  I'll find exact codes later ,

What do I need to check on that ecu cable ?

Cleaned the tb and mass air flow sensor , changed plugs and air filter and a service still not much better .