Cable ties

[Kev0607]

That's just a generic code really, but I have read another post from someone who had the same error using a generic code reader. To get the best answers, it needs a proper scan with Volvo diagnostics. Generic code readers are... generic.

As you get that error when going uphill, this would mean that the engine is more under load as it tries to carry the momentum of the car up the incline.

You may have a split hose. Likely one of the hoses going to or from the turbo/intercooler. Its common for them to split with age and this is what the issue was with the other person's car who had the same generic code as you. That's only a guess though. It could be many things. You could lift the bonnet or have a look underneath the car to see if you can see any hoses that are perished. Or get a friend to rev the car whilst you have a look.

Any whistling noises at all when you put your foot down?

I don't think the pipe with the cable tie on it has anything to do with the "reduced engine performance" message you're getting. Nor do I think the oil cap the mechanic has fitted will do anything, but proper diagnostics with VIDA would tell you.

I'm sorry to say, but it sounds to me like the mechanic you're using doesn't know what he's doing. Replacing an oil cap because there's too much air!? That's like saying there's not enough air in a tyre and filling it with air to find out its punctured at a later date (as an example*). If it was diagnosed properly in the first place, the puncture would have been found*. He hasn't diagnosed anything... what's an oil cap going to do?

You're based in Manchester according to your profile. Hallmark Volvo in Stockport or Trevor Burgess in Hyde are both independent Volvo specialists. They know these cars inside out. They're usually busy though with at least a week or maybe even two of a waiting list. Phone them, book it in and see what they say.

The very same applies to your car, diagnoses by a Volvo professional and that will take away "it could be this", "it might be that"... they will tell you straight away because they're equipped to work on these cars and have the knowledge/expertise. If it was me, I'd bring it to a specialist and let them find/sort the issue. Those garages I've mentioned would be my first choices. Up to you.

Volvo's need Volvo diagnostics. Cheap scan tools only tell you basic information.