Bank 1 - system too lean help!

Hello,

It's a Range Rover L322 4.4 V8 with engine light on.

Bank 1 too lean.

Changed:

MAF Sensor
Air Filter
4x Bosche Lambda Sensors
Fuel filter

Reckon it could be the catalytic converter? Only bank 1. Runs and pulls very well.

Thanks

Can't see the CAT would make it run that lean, have you looke a the rail fuel pressure and the injectors/loom?

air leak on inlet manifold?

YOREVOL said:

air leak on inlet manifold?

Click to expand...

That too

Take acoustic cover off...run engine and spray Brake Cleaner over the intake manifold where it joins the heads, also the rear over the PCV valve and front over the throttle body....

An increase in engine speed will indicate it is drawing the brake cleaner in showing a leak in the induction system at the point you spray!

That being said, a knackered PCV can cause this too....

Anther test is to swap the O2 sensors from one bank to the other....reset the fuel trims and see if Bank 2 starts running lean this will indicate id the O2 sensors are playing up!

Fuel pressure is good and new fuel filter was fitted. Lambda sensors swapped around but only bank 1 showing lean again. No exhaust leaks.

What is a PCV and how can I test it. I will check for air leaks