Daughter’s 2006 1.2 3 cylinder petrol. Emissions warning light either on or flashing and down on power. Tried using catalytic converter cleaner and taking for a long motorway run. Car ok on open road but when you stop or slow down at a roundabout the power disappears until you stop and restart the engine. Local garage reckons the catalytic converter is blocked and needs replacing. That could explain being constantly slightly down on power and slightly hestitiant but why would all the power disappear when you come to a stop and work again when restarted? That seems to point more to a sensor or electrical issue being reset when restarted. Any suggestions?

There is literally zero chance that the catalyst is blocked, warning light flashing usually means a misfire and a misfire is usually caused by a failing coil pack, take it to another garage if you can't handle this yourself.

Agree with above. 

Thanks chaps I’ve now looked into coil pack failure symptoms and your diagnosis does all make sense.

‘I’ll have a look at the coil pack tomorrow and check for poor connections.

Unfortunately Mrs TeeDeeEye and myself are off to France on Monday in the Yeti so cannot be on hand to delve deeper.

Will get a local VAG specialist on Monday if it’s not just a loose or poor connection on the coil pack.

I took out the coil packs and plugs to check. The middle cylinder spark plug was all black but the other two were a nice light brown.

Seems to point to that coil pack being faulty. It’s now not cutting out but still down on power.

Edited 1 July, 20188 yr by TeeDeeEye

Good work. Please let us know if a new coil pack restores full function.  

Garage agrees it should be a coil pack but say if one goes then the others will follow. Kind neighbour changing coil packs and plugs today. 

 

Just thought will the car go out of limp mode itself and is there a way to clear the fault light without an obd tool?

Possible but by no means certain that the other two coilpacks will/would fail soon, they are completely independent. Keep the two that aren't faulty as spares if you do change all three.

Fault should clear itself once faulty component is replaced.

Garage agreed that it probably was a coil pack. Friend changed coil packs and plugs but still down on power and misfiring :>(

Garage investigated and got a faulty injector code. Injector moved to a different cylinder and the fault followed it. They’re changing the injector tomorrow. Hopefully that should be the end of it.

 

Let's hope that's the end of it. Kinda shows the value of scanning for fault codes first. Surprised the garages failed to do so.

The previous garage said it had and that the cat was blocked....

This garage have only seen the car this one time.

Garage replaced faulty injector, all sorted.

Well done. Thanks for letting us know what fixed it.

Edited 6 July, 20188 yr by Wino