Hi Guys.

2005 panda 1.2 dynamic petrol with 93k miles. The car has had regular service and oil changes for nearly 15 years in our ownership, it has been running a bit shakily at idle for a little while and i had a new set of jets in ready to fit,It smelt a bit smelly on friday morning but I had a trip to do yesterday of about 200 miles, About 150 miles in the amber engine light came on.

i have today changed the jets as planned and it runs smoother, i wondered if the old jets have 'dirtied' the CAT

i have since connected the OBD11 onto it to get a code of 420 (less effective catalytic converter)

Can i ask if anyone has gone through this error and what would be the best approach, cleaning or changing the cat or the oxy sensors, what is the best order to do things in.

thanks

Tim

It's normally the post cat sensor, but could be the cat itself failing. The sensor is the cheaper and most likely option, so would go with that first.

When you say jets, I assume you mean the injectors? These rarely need changing????

if it was me. And its a bit of a pain. But I would swap the O2 sensors over. There both the same.

Not sure if they will come out after a Good run out. But I had to use a blow touch to remove mine.


Cat is normally good for at least 200K unless you smash it on a pot hole as I did or run the car long term with a misfire

Thanks guys

I think i will loosen the sensors, and look at swapping them over. then if that's not doing anything i will replace the latter one first. Along with a dose of cat cleaner and an italian tune

i should check i've got them connected correctly, am i correct in thinking the longer cable on the wiring loom goes to the lower sensor or are there any markers on them, I changed the clutch about 1.5 years ago and can not be certain i put them back in the correct connections when i reconnected everything.

Thanks

Tim

An air leak in the exhaust just after the sensor will cause strange O2 signals as air gets drawn into the pipe. Check for leaks at the joint just after the catalyst

Hi Guys

Right got some progress to report.

So i checked the O2 sensor connections and put some OXYCAT into the 1/3 tank of fuel i had in the car, ive ordered two new sensors so i could replace them both.

On thursday i had to go on a 70 odd mile trip into London so i took the car instead of a large van and part way through i put £20 of 99 octane shell fuel on top of the OXYCAT. I did the journey and got home no issues but tried cancelling the error code at various points throughout the trip.

I've been out to the car today to swap the cables over for the two O2 sensors incase i had them round the wrong way, The OBD11 then came up with 3 errors with the two new ones being 1135 1141 heater errors on the O2 sensors so i swapped them back and cleared the codes.

Next i then turned the car off. turned he ignition back on and tried cancelling the 0420 code again. out went the amber engine light and cleared the codes.

hey presto.....

just now been for a 15 mile test run to check the car feels ok and most of the journey was 25 to 45 mph. it all feels beautifully smooth and dash computer is giving me an average trip MPG of 91.5

i think i will do a brim to brim test to check the system is counting correctly.

thanks all for your assistance.

Tim

Unless you are doing 20mph downhill in top gear that dash trip computer is having a laugh. But they are never accurate. As you say, check it brim to brim on the elapsed mileage.


I always use the higher octane petrol. I have a Tesco 1/2 mile down the road so usually use their Momentum 99. Shell is ok but usually very expensive. Some say it's pointless but I find the cost per mile is much the same and sometimes a little better. The big difference is driveability. 100HP feels sluggish on 95RON but the 1200 Dynamic feels like the handbrakes is stuck. It's not exactly a fast car so needs all the help it can get.

The difference is caused by the knock sensor and spark advance. Cheap fuels cause the engine to fire the sparks later so more heat goes down the exhaust. It's also interesting to note that manufacturer's power figures are done with 97RON or higher fuel.

Hi Davet

Yes the computers can be out, our multipla under read by 18% but thats now gone.

I drove from high wycombe to Hearne Bay very carefully "with an egg under my foot if you know what i mean" and the instant read out was up and down but the 120mile trip average came up at 90.1 mpg.

Hence why im doing a brim to brim test and will be filling up at the same pump etc. i will keep you posted

Tim

68 is the best I have ever got
61 is quite easy

Mine reads bad for about the First 150 miles after the battery been off. Doesn't seem to coast correct. Down hill foot off usually shows 141.1 but struggles to get there for the First 100 miles. Also 66.6 is quite a common number


not sure whats going on but the total miles left start not too bad. Goes way off then comes on track again



because is an average when you press the reset button affect the result. if you press it going up a steep hill, it will be ages before it drags the average back up. Same if you are costing down hill @141.1 for a couple of miles. It will take ages before it dragged back down.



I use to reset the trip computer every time I filled up now I leave it alone the average over 4k is pretty much spot on

Hi Koalar

I dont disconnect the battery all that often so not aware of what effect that has.

Generally i find the range readout seems to look at the last 1.5 to 2 miles and works out the range based on your use over that last distance. its also amazing how much drop of of the overall economy average figure when the car is run from cold to warm over the first mile or two, i would imaging the car uses about 40% more fuel while warming up. i also found that driving in wet conditions seems to reduce the economy by about 15% due to the water drag.

I still have the thermostat now to change as the temperature falls away from the centre of the gauge going down long hills, the ECU senses the temperature from the sensor on the casing so currently the car runs rich when getting to the bottom of hills. i must remember not to take the radiator cap off when i do it.

Tim

car warms up much quicker if you don't use the heaters.

keep the fan speed off or one really speeds the warm up period. Mines quarter of the way there within the first few minutes

All these little tricks we can employ so as to reduce our carbon footprint

How old is the coolant? If its unknown just drain the lot flush with clean water and use new coolant.

Hi Dave

Thanks for the thought, the coolant was all replaced in april 2017 when the second water pump was done when the fourth belt was done, as its the red type its got a 5 year life so i will probably top it up with 100% red and not dilute it.

its good to have the heads up on the "don't remove the rad cap" though

Tim

timmycm850 said:

I still have the thermostat now to change as the temperature falls away from the centre of the gauge going down long hills, the ECU senses the temperature from the sensor on the casing so currently the car runs rich when getting to the bottom of hills. I must remember not to take the radiator cap off when I do it.

Click to expand...

Leaving the rad cap on won't help you; you need to lower the coolant below the level of the bottom of the thermostat housing, or it'll go everywhere.

The easiest way is to syphon it out; if you use clean equipment, you can put it back in after you've changed the thermostat. Plan on removing about 3 litres.

Access is straightforward once the battery & battery tray are removed; you should be able to unbolt the coil packs and ECU carrier, unclip the cables, and position the ECU & cables out of the way. No need to disconnect any wiring.

Hi.

Yes i have clean hose i shall do that first, the water/anti freeze is very clean at the moment so should go back in fine.

I might wait til its a bit warmer tomorrow ie in the afternoon.

yes i moved all the wiring without disconnecting when i did the clutch 18 months ago so it does move fine as you say.

Tim