Catalytic converters/front pipe flange

Hi all,

Earlier in week my girlsfriends car started making a horrendous rattling noise and upon inspection I noticed a couple of sheared bolts connecting the bottom of the catalytic converter to the front pipe.

Has anyone attempted to drill and re-tap the holes? Any advice I’d prefer to not have to replace the entire cat if possible.

I’ve attached an image of the current state of the flange. I believe I’m missing some parts is anyone able to identify any of them for me?

Thanks in advance for any help



Use a screw/bolt extractor with left handed drill bit (Have not used yet but have a set that I plan on trying various bolts)
Heat them up method (worked today on a smaller bolt Heatshield)
Last method stand drilling for a whole day then re tap

Edit :- Another removal method for bolts/broken studs. When heating up candle wax seems to work on broken studs or bolts as it melts down into the threads.
Provided you can get a hold of them otherwise drill would be the only solution.
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Looking to renew the cat on her 2006 1.2 next month and wondering if anybody has any done this? Seems fairly straight forward involving 6 bolts connecting to the manifold and 2 bolts with springs connecting to the front pipe flange... but I'm sure there will be some difficulties with it and would really appreciate any advice from anybody who has done this. Have cleaned up and soaked with penetrating fluid and will do again a couple of days before tackling this.

Of the six, the bolt nearest to the engine has the most restricted access and would prefer not to remove the manifold...
Thanks in advance.
Okay so you could also use a cutting wheel to remove the damaged bolts.

These bolts won't budge. So I'm now thinking should I consider using a different tool. Since I have so far been unable to attach the ratchet due to not enough room.

Was trying with mole grips or vice grips as a last resort. They just seem to jump off.

So bolt extractors or dremel cutting wheel the latter being the lastest resort.
I have not used the Blowtorch as yet since it seems crazy to use an open flame in the engine bay with the limited space available..


I had the EXACT same thing.... took the car to a garage and the mechanic put the OXY torch on both studs until they were red hot and he extracted them easily with grips. No need to re-tap, the new bolts went in fine.
Just to follow up, have just received an mot pass with a few advisories that will be sorted in due course. Gave the catalytic convertor removal and replacement to a guy recommended to me locally and he did the job with no fuss or problems by removing the two bottom bolts and the manifold from the engine to enable the cat to be removed away from the car. A week earlier I had soaked everything in penetrating fluid after cleaning up with a small wire brush- not sure if that helped. I provided the cat and fitting kit and he sorted out new bolts for the cat to manifold which were not included as part of the fitting kit.