has my cat collapsed?

Author
Discussion

lel

Original Poster:

395 posts

122 months

Saturday 22nd August 2015
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My 1.7 Puma has lately lost power, developed a rattle and has started coughing and spluttering at higher revs. When it started i had a whispy air noise, sounded a bit like a blown manifold gasket but it was alright, then the rattle started then the loss of power.

The car drives fine at lower speeds apart from the rattle but once you try and open it up the video shows what happens, sort of feels like fuel starvation.

I've had it plugged into live data to check the 02 sensors, No1 is jumping from lean to rich as normal and No2 is doing the same, which i believe it shouldn't?

video: https://youtu.be/gqqzSCCUyWY?t=1m2s

George111

6,930 posts

250 months

Monday 24th August 2015
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Can you not take it off to have a look ? Are the symptoms you've got best described by a blocked exhaust ? I've never had one that I know of.

andyiley

9,105 posts

151 months

Monday 24th August 2015
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As above you need to get it off to check, but I did have exactly that on a 523i bm a few years ago, it would not rev above 3000 rpm at all.

one eyed mick

1,189 posts

160 months

Monday 24th August 2015
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Collapsed cats are common in the real world I personal have had a number, mainly on well used light commercial vechs signs are many from not running at all to lazy perf or horrendous rattles it need fixing with a new one or taking out if its old enough!

Sardonicus

18,928 posts

220 months

Tuesday 25th August 2015
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lel said:
My 1.7 Puma has lately lost power, developed a rattle and has started coughing and spluttering at higher revs. When it started i had a whispy air noise, sounded a bit like a blown manifold gasket but it was alright, then the rattle started then the loss of power.

The car drives fine at lower speeds apart from the rattle but once you try and open it up the video shows what happens, sort of feels like fuel starvation.

I've had it plugged into live data to check the 02 sensors, No1 is jumping from lean to rich as normal and No2 is doing the same, which i believe it shouldn't?

video: https://youtu.be/gqqzSCCUyWY?t=1m2s
If sensor 2 (post cat) is switching then the cat as failed/broken up it should flat line all things being equal, I think this sounds like the broken cat is blocking the exhaust pipe on the smaller cat outlet tube scratchchin like mentioned already remove the cat and have a looksie

lel

Original Poster:

395 posts

122 months

Wednesday 26th August 2015
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update:

checked the second lambda and it was jumping all over the place, pulled the cat off and hollowed it out and the car is a little rocket now, much better.