Intermittent ignition problem and juddering

I have a 2006 Jimny, which is a lovely car, but it has been suffering with an intermittent ignition problem. The issue is most obvious after I've coasted down a hill and start to depress the accelerator. The car will judder and hesitate a little until it picks up speed. Even if I put my foot down on the accelerator it still judders, so I don't think that it is the throttle position sensor.

I've replaced the spark plugs, O2 sensor and one of the HT leads (the others seemed OK). There are no engine management fault codes.

My local garage have run some tests and notice that even when cruising the car hesitates a little. They could not identify the cause, however, they suggested that it might be the EGR value. I'm not convinced, especially as it looks difficult to access!

What would you suggest I check and in what order?

Which engine is in the car?
Try replacing all the leads, better to be safe as what looks good can be the opposite.

It is the M13A engine.

I'm hoping that I don't need to replace all the leads because the two with the coil packs are expensive. So, fingers crossed it is something else.

That's maybe so but it is extremely likely to be ignition problem than something else and is the easiest to eliminate. Try asking members if they have any good known spares as some do break the cars and sell bits. Ask on the For Sale forum.

Thanks for your advice. I'll try posting on the for sale section to see if anyone has some good spares.