[AllHailKingVolvo]

Hmm...took the car on a good run yesterday (a 2hr round trip) to work and back, and whilst it generally drove well on the way there, the misfire/flat spot had returned noticeably on the way home. However, it seemed to come and go periodically which seemed odd.

Yesterday on the car I changed the CPS and cleaned all earth strap connections all round. It ran fine when tested afterwards and generally well on the journey to my gig, it was the trip home (temperature much colder and more damp than the journey there).

I'm wondering if initially, the more free-flowing fuel filter increased fuel pressure which richened the mixture, but subsequently, if the CTS is off, the ECU has leaned out the fuel trims again as it's "learned" the new fuel flow rate etc.

I'm also suspicious of the Bosch HT leads I fitted, the boots on the king lead and cap end aren't as long and nicely fitted as the ones that came off, which themselves were cheap leads...so I bit the bullet and ordered a set of Bougicord units. I've read some negative comments about Bosch leads so figured going OEM would probably be best.

The hunt goes on...I'm determined to get to the bottom of this!