Hi guys, just after some advice. Our TL AWD, which we've had for more than 10 years, occasionally stalls when idling e.g. waiting at traffic lights. It just cuts out and you need to re-start it, but it re-starts straight away.

We had some issues a couple of years ago with stuttering while accelerating, but this may have been bad fuel and the addition of injector cleaner seemed to fix this. But I think this is a different problem.

Today I drove it, and even while cruising this time is seemed to be retarded for a split second, but then got going OK. I recently took the car to a Mits dealer, they put the computer on it but no fault was shown. They also cleaned the throttle body, adjusted the fuel/air mix and idle speed, and replaced the air filter which they said was completely blocked. The car still has the problem. They said the next thing to check would be the spark plugs, throttle position sensor, etc, etc.

The car just ticked over 200K's, up till now it's been a fantastic family car, but I don't want to keep throwing money at it, I'll just get rid of it unfortunately. My son, a P-plater, currently drives the car, and this issue can be dangerous in some situations, so any advice would be much appreciated. Fuel filter perhaps?

Thanks guys in advance.