Hi Everyone,
I am new to this thread and i am here because of the same reason as you ppl are - FIAT love , I have a 'fiat grande punto ' multijet 1.3, diesel, late 2010 model, done 1,3 lakh kilometers.
A couple of months ago, It has started to give black smoke and the pick up has reduced considerably, so i decided to use my 'icarsoft scanner'.
The first time i scanned it gave three error codes which were as follows:
1. P0430 - Catalyst system efficiency below threshhold, bank 2
2. P0139 - 02 sensor circuit slow response Bank 1 sensor 2
3. P0138 - 02 sensor circuit high voltage bank 1 sensor 2.

And since i am not so technical and did not understand what these error codes meant, i searched the net and got that something was wrong in and around Catalyst converter. so i went to a local mechanic who helped me
1.) clean the silencer, by putting pressurized water into the outlet of silencer and as a result ....lot of black carbon came out
2) clean the two sensors , (a)one was just in front of the car near radiator and the (b) second one on the upper side just behind the air filter.
And as a result of these two efforts, pick up has improved considerably and i think a little bit of fuel consumption too has improved, but the black smoke still comes out of the silencer outlet.
So i decided to again use the scanner, which now says no error codes.

Now what could be culprit, ... the sensor, relay for the sensor, or fuse or anything else. Can anyone please help, i know there would be many experts here who are capable of sensing what's wrong. I would be grateful if you could guide me.
Thanks
Satin.:worship:

Sorry forgot to mention , i ve just changed air filter, oil filter, diesel filter and engine oil after using flush.

Black smoke is usually a sign of the fuel in the system isn't getting burnt correctly I.e not enough air to fuel. You've had the oxygen sensor cleaned an you seen an improvement. This may not be where the problem is because more than likely it would reappear on a scan. Have a go at cleaning the egr valve (https://www.fiatforum.com/grande-punto-guides/178715-cleaning-egr-valve.html open in a browser). A faulty egr valve will give you poor fuel consumption. I had similar issue on a diesel and new egr valve fixed it (was stuck open so wouldn't start but was giving black smoke on start up).

Could be the turbo isn't getting enough air to fuel going through it. Or dirty injectors. Personally I'd start with egr valve as giving it a good clean won't do it any harm.

Ok thanks for the advice, i ll do what you say, clean the egr valve first, if it is turbo can it be cleaned or repaired , i mean what could be wrong with it.
Thanks

I'd also check the boost hoses, a split hose will mean the engine doesn't get enough air and runs rich.

A split hose can be hard to spot as the splits only open under pressure. They often hiss a bit though.

Also water on hose when revving should give a idea on if blowing air out and it shouldn't. If turbo more likely pipe loose or split like jameshobiecat said. Worse case scenario could be I injectors or pump but more than likely egr or hose.

Sometime you can by upgraded parts (silicone not rubber) that will last longer. I did this on a old car of mine. Had a slit in rubber pipe and was common issue on the car so upgraded to silicone. Cost that bit extra but worth it as wouldn't have replace as quick if ever

I have got the EGR valve cleaned, it was'nt too dirty but nevertheless it has been cleaned as advised by cobalt and have also got the turbo checked, the oil is circulating in it properly, though pick up has improved a bit but smoke still coming.
So i would now get the hose checked for any leakage as suggested by jameshobiecat, also suggest if the O2 sensor could be the culprit and how to check if it is working, and does it have a electrical fuse or relay ?

Thanks.
satin137

Sounds daft you not tried some good quality fuel and give it a good blast down the motorway?. I used something called bg244 injector cleaner once. Put that in with full tank of v power and gave it a good 30 mile 40 mile or so run. Car ran shot at first but after 20 miles it was great. I've never used it on a fiat and also sometimes the deposits that get unclogged can also make issues due to they was stopping issues.

I thought all sensors on a car was via a relay maybe wrong

If don't want buy new sensor to see if was that then connect car to multiecu scan (loads people on her could do that for you). Turn the car over and look at the screen that gives you all the engine details. This will give you a reading of c02 via the car

Thanks once again for the advice , i ll do that and let you know.
satin

Have you got a picture of the egr valve location on the 1.3 multijet turbo diesel

Hi guys,
My 2009 mtj punto has now clocked 125k kms. Started showing thick black smoke on revs above 1500rpm. I presume it's something similar to satin137. Ive done my services from fiat upto 75000km and then from a Bosch authorised centre. I've done an oil change along with filter changes and still persists. Guys, Please advice what could be causing this? What can be done?

As too often, IF Satin137 had completed the thread he opened with the final solution You wouldn't even had to re-open this thread ! Too many people on the forum ask for advise and never follow-up with their results neither do they thank the numerous nice guys who replied to their request, that's sad :-( I also noticed that some replies are non-sense or at least not fully true, that as well makes me angry, if you don't know what you're saying, don't !! ...

That being said let's analyse your issue:

- black smoke: unburnt diesel, that why Satin137 had his catalyst clogged (saturated), smoke is the reason, not the effect.
- before starting buying and replacing things blindly, have the ECU obd scanned and check what the curves are. Look at fuel and boost pressure requested vs actual, found a mismatch here ? You get the right direction to investigate.

BTW: a diesel engine doesn't run lean or rich, it just burn the diesel it's given. Once all the oxygen is consumed, the remaining diesel (if any) goes to exhaust as black smoke...

Regards, Bernie

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