155 THP misfire and power loss

[Safe-rider]

I've read numerous threads on here regarding the dreaded misfire on the THP engine. I've got a 2012 155 THP with 35000 miles. It has a slight misfire which gets progressively worse, loses power and the engine management light comes on. I've had it on diagnostics and is shows no 1 & 2 cylinder fault. I've replaced plugs and ignition coils and still the same problem. I've had the high pressure fuel pump replaced and still the misfire. Obviously this is getting expensive and the fault has not been rectified.

Has the cause of this fault ever been found. It seems to be just trial and error and a lot of expense e.g. Timing chain etc. Please help!!!!!

[mjogreen]

Carbon build up in inlet and valves?

[BeefMasta]

Carbon build up in inlet and valves?

I'd go with this as something to check too.

[Safe-rider]

Carbon build up in inlet and valves?

Is this expensive?

[Chris_Blue]

Carbon build up on the inlet valves as a GDI engine

Expensive- depends where you go. About£800 i was told at Citroen

Get to SPTuning think he does it for round £300- but best ask as I'm a bit rusty on prices

[mjogreen]

Is this expensive?

As above, get in contact with Jamie@SPTuning on the forum, he'll give you a quote.