Matiz Losing Power

[jam butty]

Hi all,
I'm new to these parts and was wondering if anyone could help with my wife's sickly Matiz.

Recently the 800cc Matiz has started to lose power and stutter when accelerating. The problem is intermittent but appears to be worse once the engine is up to temperature. There are no lights warning lights on the dash but I've plugged in my fault code reader and it has shown just one code - P0172 (System Too Rich Bank 1).

I've read around the forum and concluded that the coil packs on these cars are less than reliable so I'm considering replacing that along with the plugs and leads. Having tested the resistance of the leads I found that one offered slightly less resistance than the other two but I doubt this alone is responsible for the loss of power or poor acceleration.

Does anyone have any other suggestions, particularly with respect to the P0172 code as this has confused me completely.

Thanks for reading my post and any help is appreciated!

[Daniel]

Have you checked valve clearance?

Cold
Intake 0.15±0.02 (0.0059±0.0008)
Exhaust 0.32±0.02 (0.0126±0.0008)

Hot
Intake 0.25±0.02 (0.0098±0.0008)
Exhaust 0.42±0.02 (0.0165±0.0008)

Unit : mm (in.)

[woo99SE]

before you start tossing $$$ around Always! start with the cheapest things first.

Have you changed the engine oil at the recommended change intervals by Daewoo? is there any oils there(measure it).
is the air box filter clean?( engine air filter
How old is the timing belt?
When was the last time the fuel filter got replaced?
Are the spark plugs gapped correctly or recently replaced?
Does the car smells like rotten egg when it starts bogging down?--> clogged up catalytic converter(if equipped).
Is the radiator water lever where it should be?
Have you ever replaced the O2 sensor?
Had this car overheated recently? check the engine oil, if it looks milky(Tan color) you need a new head gasket. same if the coolant/water under the radiator cap or liquid itself has a milky slime residue. a good sign would be a low level at the water coolant reservoir. this you'd need to check periodically to notice it or by just looking at the water bottle or best with a cold engine remove the radiator cap or reservoir cap and see if the antifreeze/coolant level is way low.

I you have a bad catalytic converter, the best thing to do is to bring the car to a shop and have them replaced it. don't put this on hold, if you drive the car at late evening and the car starts to chug get to a safe parking lot and look under the car's carriage, look for the catalytic converter if it is CHERRY RED HOT guess what? yup you need a new CC. you should be able to smell the funky odor from the CC. btw if the CC is clogged up it can catch fire. FYI!

Once you have regapped the spark plugs and checked or replaced the Air filter add a bottle of fuel injector cleaner to the fuel tank then take the car for a brisk spin(safely!!).

I'll leave you with that for the moment, there is more..

gl