Thank you for your help. First run before the chip it ran a peek of 198bhp. The oxygen sensor should of been up to temprature as he went to lunch at this point!!! Definetely warmed when he got back!!! But I see your point with the fan they use at the front. The fuel as I understand it was to rich and it was leaned off. The initial results seamed really good and it picked up at lower revs quicker. I even had an average of an extra 3mpg!! but not for long as it reverted back to its old self. But no adjustment got rid of the power dropping and picking up again. The exhaust including the cat was replaced about a year ago with a stainless steel and someone has suggested that the cat could be a problem but this was in relation to its stutter (which I forgot to mention). Apparently technicaly a flat spot its at very low revs and accelerating in second gear the engine stutters. Get the revs up a bit or in any other gear its fine. It has done this though since I bought the car long before the exhaust was changed. Spark plugs. Now theres an idea. They were replaced about six months ago but I dont know what was fitted. Rekon I might have to find out. Like I said not a mechanic I think your refering to the spacing at the actual spark between the 2 conductors. If I buy and fit a new set of spark plugs, decent ones obviously I assume the spacing is correct out the box and I just bolt them in?? Its also had an induction kit in place of the air box so that should of got it a little up from normal but 204bhp that has been mentioned somewhere as a standard car figure. If it was 24bhp down on the quoted figures then it had already almost made that up. Anyway it was decided as the ecu had obviously been disconnected it had reset and to simply drive it until the ecu calms down then try setting it up again. Goes back in friday so I will soon find out about that one. Just a final thought.... Old spark plugs from memory were black and oily which is a sign of over fueling possibly from what I can remember. Six months later and I assume therefore the new ones would most likely have gone the same. Think I get and change the spark plugs before friday.