got a little problem with my ford focus, car starts fine, it goes fine, does not splutter of cough and runs, but it feels like it lost some power, it is a 2000 1.6 focus, it struggles going up hills, ive dont all the leads and coils and spark plugs, noticed abit of oil on one of them but am sure thats not the problem, fuel filter fine air box is fine, any ideas cause its confusing me, ive just put new standed ford focus wheels on which are 15" and new tyres, which are 195/65/15 and it just happend soon as i did that, so thought it could be the drag from wheels but i very much dout it

any ideas you kind people

thanks

It wont be the wheels without a warning light or fault code it could be anything cars will lose power going up hills thats a given if the car can hit 70mph its not restricted so it could be clutch slip it could be a fuel filter issue so many things its hard on a forum to know how much power its lost any other issues with it bad idle etc if its not coughing or spluttering and running okay ide look at brakes binding or clutch slip oil on a plug suggests worn rings which will effect performance

new plugs ive put in to, just had a look at the cat, give it a shake and there sounds like something is shaking inside that, i know that not normal lol, could explain why it struggles, the air is not flowing right and reading someone else's topic, everything is the same, no engine light on or anything

Loss of power , using more fuel than usual ?? Noisy cat (meow) new cat time for sure ....... :D

Clutch slip, might have run out of meat! Or possibly a vacuum/air leak. I bought one of those inexpensive OBD-2 readers that plug into ur PC using USB connection, there are Bluetooth and 802.11 WiFi enabled OBD adapters as well. They allow programs on your computer to interface with the car's ECU, sort of like a specialized CPU but for cars. Anyway, get something like an OBDLink SX, update the firmware on it when you get it and then download an OBD-2 software like ScanXL or similar that identify the PID codes. You can do things like watch cylinder head temperature, camshaft and injector timing adjustment/retardation in real-time, fuel-air mix ratio and trims, O2 sensor bank monitoring, emissions readiness tests, misfire and knock detection and so much more. Get on it...

i have a friend who has his own little garage, he very handy to know as he got a snap on ecu reader, last time he check it ws working ok but after reading up different storys, am putting my money on the cat, in the isle of man, you dont need to have a cat to mite just go for a de cat, will that send the ecu reading funny for the o2 stuff lol, clutch feels fine mate but thank you all for you help