Technical Possible Catalytic converter issue

[fiatireland]

Hello all,

Have been have a lot of issues with my poor Panda lately!

Its a 2006 petrol 1.2 and the power is dramatically down. Max speed is about 80km/h and it takes an age to build up speed

There is no misfiring and the engine seems to idle really well. There are no engine warning lights and code reader does not return any error codes

There was in the past a misfiring issue and maybe its possible excess fuel may have damaged the catalytic converter

I took it for its MOT/NCT and it passed emmissions ok

Local garage believes it is a catalytic converter blockage but they dont seem to be absolutely sure.. Is it possible the emmisions are passing with a blockage?

Before spending so much money on a new catalytic converter, does anyone with experience of these type of failures have any advice or any way to confirm the converter is blocked?

Thank you

 

[porta]

See @koalar thread on this…MAF sensor cleaning is an obvious place to start, but anything from coils, plugs, leads, breaking down under load

 

[fiatireland]

See @koalar thread on this…MAF sensor cleaning is an obvious place to start, but anything from coils, plugs, leads, breaking down under load

Thank you - sorry should have included that all plugs coils and HT leads were already changed and the MAF sensor was ok.

 

[koalar]

There's a lot of way to start this

If you believe the garage then measuring the back pressure is a 2 minute job but you need a pressure gauge or pay someone to test it 100% reliable



A quick and dirty test with a cheap handheld scantool,

Plot the MAP sensor

Idle 20 seconds
2k rpm 20 seconds
3k 20 seconds
4k 20 seconds

If it's steadily rising is pointing towards a block CAT

Or

Disconnect the O2 sensors and take it for test drive, the engine check light will be on

Then

Remove the pre CAT O2 sensor and take it for a test drive

There should be no noticeable differences between

Restricted exhaust on these engines are very rare, it does happen, I know of 1 confirmed in the last 10 years


If you think the garage is is spinning you a yarn, we can go a different route, there is literally 100s of different causes for a performance issue

 

[koalar]

Is it possible the emmisions are passing with a blockage?

I don't know

 

[The Panda Nut]

I don't know

Unlikely. The gases must pass through the cat for it to work. Is it fly by wire throttle body. Can you observe it opening fully as the throttle pedal is pressed. I would change the MAF again and look at the throttle body, and fuel delivery pressure.

I have had cars that ran badly misfiring and running on 3 rather than 4, and I was expecting cat damage but none ever occurred so you would be unlucky. They seem to be more resiliant than you would expect.

My thoughts, restricted fuel, restricted air, lack of oil pressure, binding brakes. Fuel starvation seems the most likely thing.

Does the car rev freely without load? ALso check you havn't half swallowed a bird in the air intake.

 

[koalar]

Unlikely. The gases must pass through the cat for it to work.

Some decat cars still pass the emissions test but should still fail because it's been removed, I have no idea whether a decat fiat would pass without a CAT or not

Is it fly by wire throttle body. Can you observe it opening fully as the throttle pedal is pressed. I would change the MAF again and look at the throttle body, and fuel delivery pressure.

No need to change anything yet, these are MAP only engines, as far as I know no diagnosis has been carried out yet, fly by wire throttled do not open full while sat in neutral, even if you push the accelerator to the foot, not recommended, 2006 1.2 could be either flyby or cable

I have had cars that ran badly misfiring and running on 3 rather than 4, and I was expecting cat damage but none ever occurred so you would be unlucky. They seem to be more resiliant than you would expect.

Correct, very rare

My thoughts, restricted fuel, restricted air, lack of oil pressure, binding brakes. Fuel starvation seems the most likely thing.

Dees the car rev freely without load? ALso check you havn't half swallowed a bird in the air intake.

Might be any sensor to do with fueling, anything to do with spark, valves, timing, compression and so

I gave some pointers in the last thread as a starting place

@fiatireland has previously had a problem with the ECU controlling the coil, as far as I know we haven't checked if a spark is indeed present at each plug


With very little feedback, very little information to go on, we aren't going to get very far, just a long list of every possibility thing

 

[MrMagoo]

When was it last serviced? Is the throttle cable operated?

 

[Yolanda]

How much pressure is coming out of the back box/tail pipe. Rear silencers have been known to break up inside and restrict gas flow.

 

[fiatireland]

Thank you to all.

I have had many issues with my poor Panda lately, ECU, Wiper motor, battery, headlight adjusters and clutch. Last one remaining is the lack of power so hopefully this can be solved. Now that the clutch solved I can drive it to seek diagnosis.

Briefly : The car was in a garage for misfiring. He changed the plugs leads and coil packs. He eventually gave it back unrepaired and stated it would be too expensve to repair. However when i looked closely at the ECU connectors there was a pin slighly bent and repositioning it cured the misfiring but the car was left with low power which maybe was added when he changed the parts while misdiagnosing

So I brought it to another garage and he tested all cylinders were firing etc and diagnosed a blocked Cat. However the same garage also dignosed a full clutch replacement was needed due to a sticking clutch pedal when all that seemed to be needed was a slave cylinder - so I am unwilling to accept that diagnosos without a second opinion. Now that it can be driven again I can seek that. Which is why I asked in this thread if there was a way to easily check the catalytic converter. Also it Passed emmission tests so I am sceptical its blocked

Anyway I think I will start from scrath with the low power issue and update - Thank you all so much for a fantastic forum

 

[koalar]

Why not start at the begining and

Diagnose it for yourself

Post a video 5 seconds or so of the exhaust don't get too close need nice clear audio

Do you have a scantool

 

[MrMagoo]

Appears your garage is not competent, and I suspect possibly bent the ECU pin in their failed diagnosis.
It is interesting you've had some other electrical gremlins - have you checked your engine earth strap? It's s a very common failure and gives all sorts of weird running and errors.

 

[Mike1alike]

Which is why I asked in this thread if there was a way to easily check the catalytic converter.

There is. Connect a tester and read the O2 sensors (Lambda) values. Record a graphic of those, idle and revving, the post cat sensor numbers should definitely tell you if it isn't working.

 

[koalar]

There is. Connect a tester and read the O2 sensors (Lambda) values. Record a graphic of those, idle and revving, the post cat sensor numbers should definitely tell you if it isn't working.

We not testing for emissions, we are not testing for CAT efficiency , as in this test

Back pressure is the correct quickest method, as per post 4 there are others more subjective methods such as measuring heat at the front and back of the CAT or measuring MAP at different RPMs

With no test equipment just see how it runs without any feedback from the the O2 sensors by disconnecting them, then removing the front O2 sensor or loosen the exhaust manifold so it can breathe if there's no improvement there's no blockage

I doubt myself the CAT is the problem

 

[Yolanda]

Might be worth a look at the valve timing, the belt could of jumped a couple of teeth. It's a case of checking everything as you seem to have done quite a comprehensive check emissions wise plus what the garages did with plugs/coils etc. It's now a process of elimination.

 

[fiatireland]

Thanks so much everyone.

@koalar - I have recorded a brief video of the exhast hopefully the sound is ok but there might be too much external noise

also a little clip of the engine idling:

The code reader i have is very basic so I ordered a slightly better one with live data and better features I hope

@Yolanda Thank you - the mechanic said he checked the timing belt was okay and it was replaced about 2 years ago - but I may get that check again

@MrMagoo Thanks- I think earthing was ok but will recheck it

Mike1alike thank you when I get the new scan tool hopefully i can check those

 

[koalar]

Sounds like it's firing on all cylinders at idle to me

Here's mine to compare

 

[fiatireland]

Thanks Koalar - yes I think so too and it idles without vibration or shudder.

I think your idea about checking for breathing sounds sounds good- I will try removal of the o2 sensor to see if its related to lack of air - is the o2 sensor easy to remove?

 

[Yolanda]

Fairly easy if you have the correct spanner.Do it with the engine hot they tend to come out easyer.

 

[koalar]

I use a normal 22mm ring spanner on a hot engine, the connector just fits through the ring end, just be careful not to round it off, normally there are fine, but once I had to break out a blow torch and heat it to cherry red before it would come out, there's no way of knowing if it will come out easy untill you try

There are special sockets just for doing this job