Flat spot at 2100rpm

[EdmundIJones]

My 206cc (MY 2001 - pre facelift) 2.0 Petrol was having trouble last week - it would rev but not much power, I had it in the garage and it was diagnosed with the cat breaking up and clogging the pipes. For the time being the contents of the cat have been removed so I can replace the whole thing when I can find one at a reasonable price.

Now it's running on what appears to be full power which is like it used to be, BUT, it's developed a flat spot at around 2100rpm, it's only momentarily it just creates and unpleasant feeling when driving, could this be related to the cat removal or do I need to start looking elsewhere, any ideas?

[GrandadMonkey]

The flow through the exhaust will have changed if the cat has been emptied. It is probably tending to run weaker now. I'd get the exhaust repaired so that it is back to specification. That will probably cure the flat spot in itself.

If you don't do one thing at a time - i.e. cure what you know to be wrong - you could end up chasing your tail.

[Capncol]

If you don't do one thing at a time - i.e. cure what you know to be wrong - you could end up chasing your tail.

Wise words indeed!

[EdmundIJones]

That's what I suspected. Other than the flat spot the engine is smooth, stable and just right.
I've got a few other jobs to tackle also like brake disk replacement, I'm going to do the fronts myself but the rears look a bit tricky where the handbrake is concerned so best left to a pro.

[Capncol]

I did a "how to" on disc replacement. It's on the site here If you fancy having a go.

[shadow]

you don't need to remove the hand brake cable to do the rears its easier than the fronts to do. i did my sons xsi last weekend 30 mins each side,remove anti rattle clips, remove shim clip, remove pad retaining shim by knocking it from the inside to the outside, remove pads, loosen torx for disc, undo the 2 carrier bolts (17mm) use a socket for this and maybe a bar for leaverage, once done remove disc, wind back the piston, clean everything up and refit put some thread lock on the carrier bolts after tightening up. of course you have to remove the wheels first but you know that

[GrandadMonkey]

I agree. Col's "how to" is excellent. I wouldn't be afraid of doing the rears if you are confident doing the fronts. Just make sure you get the correct replacements.

I take it you've got a little wind back cube, or similar?

http://www.amazon.co.uk/Draper-52334-8- ... 097&sr=8-2

[EdmundIJones]

I'm doing an oil change and front brakes disks and pads on Friday, parts ordered yesterday. The rears have a bit more life left in them so I'll want and see how things go.

I've not solved the flat spot yet but we think that it's being caused by the throttle potentiometer being warn at the most common spot where people drive. I also has word from the mechanic that he gave the car a good look over on the ramps and thinks it's in great condition and will least for years to come with a little TLC. I tend to get bored of cars and want a change ever 6-12 months, however, I genuinly like my little Pug so want to keep it running on good shape and do some learning along the way.