New CAT fitted- now engine hesitates at 70mph/ 3300RPM

[kodkod.84]

My link pipe rusted away and fell off the other day- I got the CAT replaced as well as it was looking a bit rusty and now at 70mph or 3300RPM the car hesitates and shudders like it is going to stall or backfire only for a few seconds then goes normal again.

Any ideas?

[Djmac]

I know this has nothing to do with the cat, but mine was having this issue every gear until 100mph+
Mine turned out to be the coil on its way out, and finally wouldnt start at all, so i replaced the coil and all was good, maybe wait for some more advice before going out and purchasing a new coil

[Metallix]

Damaged the O2 sensor during the installation?
Parts of the old cat ended up in the exhaust box downstream causing a blockage?

[itavaltalainen]

sounds like a plug in the exhaust somewhere....

[kodkod.84]

Thanks for replies guys- car's going into garage next Thurs for some work so will get them to take a look at this too

[kodkod.84]

Ok got to the bottom of this issue- Kwik-Fit being the spanners that they are had packed the link pipe joint with plastic wrap instead of exhaust sealant.

When the exhaust got really hot it would melt the plastic and expand making a hole in the joint as they had used the wrong size clamp so the exhaust flow was interrupted

What a bodge! 

[Therusterman]

Oh, that's not good. You going back to Mail Fit to see if this is standard procedure?! Glad you got it sorted