Originally Posted by Tim Crump
There have been some threads that have caught my eye

One about CRC GDI valve cleaner CRC Valve Cleaner

and another regarding Cat Cleaner Cat Cleaner

My Plus 4 GDI has done 25,000 miles
Not long after I purchased the car I replaced the exhaust manifold and cat with one from Librands, probably the best thing I have done as it transformed the engine.
Other applicable mods are Dave W's breather modification
and his wrapping of the air intake pipe with heat shield

But in recent months I have noticed a developing hesitation a bit like someone lightly applying the brakes, Also an increase in the pops and bangs when taking the foot off the accelarator and coasting.
When cold I have to be a bit more aggresive with the revs and get caught with Kangarooing sometimes!

So far I have
Changed the plugs, there were rather black, but no percived difference
Swaped the MAFsensor but no percived difference
Changed the air filter, now that did improve things but not cured

So now I'm thinking of using
Catacleam for petrol this is just a pour in the tank when about a third full
and possibly
CRC GDi cleaner

But would be interested in other forum members ideas.


If the plugs were black that indicates the mixture is too rich, Consider Lambda sensors.

Keith
2013 narrow bodied + 4 Ruby.