Hi - The last few weeks I have been getting an intermittant catalytic converter fault shortly after switching on the engine - usually when its cold in the mornings, I switch on the engine, the car judders around as if its freezing or a blockage in fuel etc. (if you know what I mean) then the light comes on, I switch off the engine and give it a minute or two and start her up again. Sometimes it comes back on, other times it doesnt, and as soon as the engine has warmed up a bit I turn off the engine and back on again and she purrs like a kitten! Ive tried filling her up with premium petrol and its not made a lot of difference, also I have taken the battery off to reset the ecu, but it still does it --- usually once a week - on a friday!! any ideas please,, I cannot afford to spend another £500 on it!!!! heeeellpppp ;-)

Kerrie, January 2009

go on a motorway and keep it in 3rd gear and go 50mph or a touch more for 10+ miles, this should heat up your cat enough to declog itself

Mitchell, October 2021

I live in the Uk and I too have the same problem with my Peugeot 307. I am kind off giving up on this car as I have spent a lot of money over the past few years to keep it running and healthy.

It started with a loss of speed and the engine light flashing and beeping with an occasional cat warning or air pollution warning pop up on the little screen. This would go after I ran the car for ten minutes, turned it off for 5, then hey presto. Everything was fine.

Now the problem has developed and the engine light always stays on with either the cat warning or air pollution warning coming up reguarly.

I was quoted £460 from a Peugeot garrage for a diognostic and a new cat. (If that be the problem)

Then went to an Exhaust specialist and they will replace the cat for £205 and I can get it linked up to the diognostic machine down the road for £48.

This I thought reasonable as the part costs like £150 for the 307 from europarts.

Reading the comments I am not sure what to do, may push it off a cliff. But any further advise appreciated.

Patrick, February 2016

Hi, my 307 has just had new spark plugs, coil pack and a full service and within 24hrs it's got the management light back on and running really rough reading catalytic converter fault and anti pollution fault! Peugeot this is a joke!! It's just cost me £400 to do 50 miles!!

Lee, December 2013

i live in nigeria and i also drive a 307 and this morning, for the first time, it flashed the message "catalytic converter fault" "air polllution". it shuddered when i started it and i simply parked it right back and came to the internet in search of ideas. to my chagrin i found so many drivers of 307 have had the same experience. i just bought mine 5 months ago. i am truly disappointed to find now that this has been a problem with peugeot and i didn't know.

Mamahannatu, July 2013

hallo lived in kurdistan region onrth of iraq I have a car peugeot 307 model 2005 in has a problem write in a screen of car (CATALYTIC CONVERTER FANLT) please explain to me what i do to it please

RAIKA ROSI, November 2012

Well the cold weather is back again... Had my 307 for about 4 years, and as soon as it starts getting cold, I get the cat fault again. In the past I have just left it for 10 minutes, and all is ok! Stupid car... Just started my engine again (after 10 minutes) and so far so good... Lets see if it gets me to work!

Steve Tye, October 2012

I have had the same antipollution fault warning, so, I spoke to a mechanic friend of mine. He told me to remove the sensor that's on the cat, it looks like a spark plug with a wire connected. What you do is screw it out, cable tie it up out of the way (not onto the hot exhaust) there it will pick up fresh air so you get no warning lights coming on. The hole is then filled by screwing in a spark plug. So the question is,,,, Did it work?................HALLELUJAH HALLELUJAH YES IT WORKED, YIPPPPEEEEEEEEE.

Brendy58, March 2012

Have the same fault on Peaugeot 307sw. Seems to occur when the engine is under load. Had the sensors changed but made no difference. Used a lot in europe, motorway driving is fine, only happens on short journeys. Still trying to fix. Will let you know if it is ever cured.

Rob, April 2011

Have had the problem on three occasions. On the first two occasions it righted itself after half a mile or so. On the third it was more persistent and I took the car to a Peugeot dealer who diagnosed a high-tension electical problem and replaced the lot including the plugs. I looked back at the service records and previous incidents and wondered if it was simply the plugs that were the problem. All incidents took place around 15-20K miles after the previous plug change.
Have just had the problem again, but at 8K after the plug change so I am now not so sure. Anyway a plug change may help and it is cheap to do. Worth a try?

Ken, March 2011

Europarts provided a cat converter for my 206 for 120 pounds inclusive VAT - relatively straight forward to replace - one electronic plug to remove and a set of spanners. About and hours work. Garage wanted 350 + VAT. 307 around same price - and they deliver

bruce, January 2011

This is ridiculous now, this seems to be a very common and very epensive problem with the peugeot 307. I had a 206 for years and never had any problems with this car iv had it 4 months and iv paid £500 to replace the clutch, £100 for an alternator to be replaced, £160 for new tyres and now this repair is looking like another £500-600 to repair. Really loved this car but soon turning to hate!!!
From what iv read it can be 4 possible problems all of which other commets have mentoned.

rnv, January 2011

Just had a quote from my dealer for the same fault and it is costing for the part only £544.00. Sigh....have to get it can't do without it

Just 2 Cute, September 2010

I have had the same problem i.e engine management system light came on. The car was at the right temp and was running fine. Had a diagnostic check done with Peugeot and the print out indicated that the car had an after market cat fitted that was too small for the engine and couldnt do the job. I hasten to add that the car runs really well. Have you all noticed that this seems to be an issue at around 40 to 60 K mileage? Also the CD system has now refused to work, still like the car though.

Keith, December 2009

Just had the same problem . We have had our 307 from new and never a problem in five years . Car has done 58000 miles and all of a sudden today car shuddered and the catalytic converter fault and Anti pollution fault warning beeps up.

Checking on the web there are literally hundreds of people with the same problem. Peugeot seem hopeless to sort it out.

One mechanic suggested changing the sensors and making sure the car is never less than 1/2 full and to use high octane unleaded.

Anyone else with suggestions?

Sleepy Elephant, August 2009

i have had the exact same problem so i took the car for the computer check and it came up that it was to do with the spark plugs and the cover that goes over the top which is called a coil, all this means is that it was letting too much fuel through whiich then makes the cat think it is faulty therefore you get the cat light come up and the car goes all shaky which shows that the fuel is choking it, i ahev been quoted that the coil cost 120.oo pounds and the spark plugs at twenty punds which is alot cheaper that a new cat

sarah england, August 2009

Hi, im living in spain and its around 40 degrees here at the moment, the same message has appeared in my 307sw - "fault catalyctic converter".... etc. i have looked through many forums but all i can find is people with the same problem (but in colder conditions) but no solutions.
I know that when i accelerate now the exhaust blows and the engine shudders, when driving the engine is very weak..... I have heard that the fault could be from broken exhaust mountings causing the cat the brake away from the down pipe.
I have just looked under the car whilst accelerating and the cat. moves quite violently. The past couple of months before i recieved the fault message i have heard a lot of squeaking from the exhaust system... could this be the cause??

Please help!!!

Jonathan, July 2009

Hey Kerrie,
I've experienced this same thing for the first time this evening. been searching on forums about the problem.
How did you resolve it? did it need a new catalytic converter fitted? if so , how much did it cost?

thanks,
Ritz

Ritz, February 2009

maybe its getting the friday feeling? no seriously why is it a cat fault? sounds more like a cold start valve.cats dont really go wrong.try a diagnostic check

mike, January 2009