Freelander 1 Keeping Cutting Out & Revving When Idle

Hi, I have a Mk1 Freelander TD4 2006 Automatic, when driving the engine intermittently cuts out and can take a few attempts to get it started again. Also when it is in 'Park' or I have the foot brake on the engine will rev, not massively, but enough for me to feel it pulling forward when the brake is on then goes down to the point where it nearly cuts out, and sometimes it does cut out.

Any help here would be much appreciated. Don't know if its relevant but the air filter was recently changed.

I don't know if it would cause the issue your describing but it is easy to refit the air filter cover incorrectly so that it doesn't hook in at the back. Might be worth having a look but you'll need a suitable long allan key.

I'd be checking the fuel rail pressure sensor for corrosion. That is a classic symptom of corrosion in the plug.