hi, have a 2000 shogun pinin gdi from new with 180,000 miles on the clock which is now showing its age. struggled to get through an mot last few times due to emissions but thanks to some "help" from the garage managed to scrape through. Now though, new rules have meant its failed. Main problem is high co emissions. requirement is o.3 at fast idle, mine is about 0.8. Tried usual stuff, air filter, lambda sensor, new plugs but think theres a more fundamental problem. It runs perfectly well, idles smooth and mpg on the readout is 30+. keep reading thoiugh that the GDI engine is prone to carbon build up. Looked in the throttle body which actually seems pretty clean. can see some build up lower down, maybe 4 or 5 mm build up. would this build up throughout the whole inlet manifold cause the emissions failure given that its running perfectly.. Also if i do decide to remove the inlet manifold to de coke it, is it a reasonably straight forward job? looks pretty straight forward, just unboltin stuff then putting it back on, but are there any odd bear traps i should be aware of? many thanks, Mark.