A little update: I've fitted a near complete new exhaust system to my Hippo, and its back on the road and now safely back at my place
I'm so happy to have it back!
This is the first exhaust system I've changed (there's usually a good reason why I'd elect to give this job to someone else - the need for oxyacetylene being one!) and the bits I thought would be difficult were easy and the bits that I thought would be straightforward weren't. Sounds about typical doesn't it?
The down-pipe/ catalyst system separated really easily from the exhaust manifold. It looks to have been apart before insofar as the bolts used seemed a little undersized (M6) and longer than they needed to be. They weren't overly corroded either, and after penetrating oil and a clean of the exposed threads with a wire brush, it came apart very easily. Perhaps the now mullered down pipe had been replaced in the past? It looked to have been OEM though - so a great shame that the thief destroyed it. I've replaced it with an aftermarket pipe (eBay to the rescue), which fitted very nicely. Pleased actually.
The mid-section to back box section is a slip joint - and that was a nightmare to separate. Fortunately, we were doing it at Philip's place, and he has a mate with an oxyacetylene torch, so luckily we were able to remove the remnants of the old mid section from the back box after heating the pipe to cherry-red.
The back box on the car looked outwardly new, but was full of oxidised steel - I presume that the internal baffles are disintegrating? It went back on; it isn't noisy, so hopefully okay (for now).
The replaced mid-section was pretty rotten. It probably had another year may be two left in it, but that's all. The catalyst thief just hastened the inevitable here I guess.
I had to replace the post-catalyst sensor. This could have been a nightmare: it feeds down through the chassis floor, and I thought I'd need to take out the whole interior to get at it. Fortunately, that's not the case: on my 2001 FL1, I only needed to pull up the gear lever gaiter to get to the top of the lambda sensor to disconnect the connector and push the sensor out downward under the car.
The new sensor is screwed into the post-catalyst sensor boss, and then the weather proof rubber seal is pushed upward into the floor pan and the sensor connected to the main harness. Worked out to be really straightforward - shame I had already removed the centre console and was about to attack the dashboard before realising the simpler option!
On replacing the mid-section of the exhaust, I discovered the reason why, when fording a deep puddle on Salisbury Plain last year, so much muddy water had got into the car. Someone (not me!) had failed to replace the handbrake water seals in the floor pan!
Very lazy workmanship. Getting the seals to seat properly took some effort - so I can see why someone hadn't bothered, but I was no less irritated. Moral: never let anyone else work on your Hippo! (At least, not unless you trust their work!)
Annoyingly, the fitting kit I bought off the internet (for a 2001 FL1) was the EU2 type, not EU3! Completely different. Internet parts listers have inaccurate parts compatibility lists - so beware! EU2 cars have 3-bolt flanges, and a two-exhaust hole manifold-to-down pipe flange. EU3 are two bolt, and a single exhaust hole - and only one type of gasket is used throughout. Fortunately, not an expensive mistake, but certainly annoying!
Interestingly, the MIL didn't come on despite a brief drive of the Hippo without an exhaust (to an area where we could work in safety) - but the Post-cat lambda electrical circuit error was logged. Perhaps I hadn't driven the Hippo for long enough to illuminate the MIL?
Finally... the car now drives just perfectly, but two new problems have been identified. First, I wonder whether the thieving scumbag had a go at the rear door, because the rear handle has now completely detached itself. Arrgh! Second, the offside diff driveshaft seal appears to have developed a leak. Double arrrghh! I'll put those new nuisances into a separate thread!
Total cost of repair - approx £100. Could have been worse I guess. But at least the Hippo is back and on the road again
