...Trim Bank 1? The car was running really rough at idle with the revs varying between 500 and 1200 rpm. I took it to a local mechanic who found a blocked breather and a split coolant hose. These were repaired / replaced. The engine runs better now but not perfect. It seems to want to stall in first gear. However the engine management light has come back on. I took it back to the mechanic who had a quick check with his diagnostic tool and it read Fuel Trim Bank 1. Has anyone seen this before and can it be easily (cheaply) fixed? I read somewhere that the engine check light is almost always emissions related.

Have another scan done were they use a program to test the individual devices as the vehicle is running and then see if that pin points the exact fault.
Out of the things that could cause it I'd say the o2 sensor is possibly at fault here , especially if the vehicle has over 100,00 kms or so on it and the o2 sensor has never been changed yet.

Hope that helps and best of luck.

Code
P0170
Fuel trim bank 1

possible causes

faults with one or more of the following

Intake leak
Air system
Fuel pressure/pump
Injector(s)
EVAP canister purge valve
H02S (heated oxygen sensor)


best wishes