Bangenomicmechanics: Help please!

[radiodanno]

Last time I asked for help on here everyone was brilliant, so maybe someone can help on this small matter?

Toyota Avensis
2.0 (3SFE)

In the last 3 weeks my car seems to be very subtly down on power. When we were away on holiday I felt the car struggle a little, but put it down to there being 5 of us and a boot full of loot. Now i'm back home and it's just me I'm confident something's not quite right.

The car runs rough when cold. There's no misfire, but the car will hop along if there's no accelerator applied. The second you apply some right foot the car will leap a bit and then be fine. This settles down once the car is warm - BUT is still apparent (less so) when hot. Let your foot off and coast up to a roundabout and you will feel the car more reluctant.

Also, I'm certain that the car has more go above 2,000 RPM than below. Much more so than when I got the car.

Obviously I may have more than one issue, but I'm after your help if at all possible. The car has been very well serviced (annually even when doing 3k a year) but is now 14 years old. Coil Packs and Lambda Sensors spring to mind.

All help appreciated.

[daemon]

Set of plugs, then coils would probably be my order.

You could probably buy one coil and move it about and see if that improves things?

[lightthefuse]

MAF sensor?

Failing that, a classic which matches those symptoms perfectly was on my old-shape V70 - the radiator hose had managed to work itself loose!

[MGJohn]

Many possibilities. There's one clue there which may not be a false indicator. If the car was a Rover and it behaved like that first thing I would check and replace is the coolant temperature sensor.

It's a Toyota and so have no idea.

[Sump]

Don't you short the diagnostic port with a paperclip and count the EML flashes to get the error code?

[radiodanno]

There's no light showing, so I didn't think there would be a trace code on the ECU. I will give it a go tomorrow.

I did wonder whether it was an O2 sensor. I had a Rover 75 hold back on power until over 2000 rpm before, but that would really kangaroo you out of the seat as you accelerated through the holdup. It's nothing like that, you can just feel the car running lumpy when cold and then hold back when hot until over 2000rpm

[inman999]

Start simple and cheap. Things like plugs, clean MAF, throttle body, egr, vacuum leak. It could be a number of things. Try unplugging the maf and injectors one by one to see if there's any noticeable difference when compared to each other.

[goneape]

I've just had similar symptoms with my tt, it was better after a service but cleaning the air filter sorted it completely. It was filthy, well time for a recharge. Nb k&n performance/reusable filter not paper single use

[leafspring]

long shot but could be a tired fuel pump or clogged fuel filter?