Bringing back to life an 18 year old Audi A8 D2 part 9 - various odd jobs continued

Next up in this never ending story is the exhaust, its old, rusty and something inside the cats rattles there's 2 codes for catalyst system below efficiency:

This basically means the car needs all 4 new cats and oxygen sensors as they're all 21 years old at this point and wont come out in one piece.

Example of what i mean by rusty exhaust:

Flex joints were torn too, but i didn't get any pics.

Video of the startup rattle:

I decided to go with BM Catalysts pattern parts as OEM Audi parts would cost around £4k going with BM parts it all came to around £557 for every part including exhaust paste and bandaids.

So, the new cats came and they were of an average quality so i had to de-burr parts of them:

After de-burring all the cats i removed all the stickers from them and sanded them down for painting with a high temperature exhaust paint, this was an absolute waste of time as all the paint came off anyway and smoked and smelled really bad after fitting/first engine start:

Old vs. New

The whole replacement procedure took 2 people (me as a helper) and about 9 hours. The hardest and most crucial point of it was removing the nuts at the exhaust manifolds. If any of the studs snapped, it would mean and engine out job.

5 out of 6 came out ok, but the last one (as it always is) put up a fight. The solution turned out to be carefully dremeling off the nut so it can be undone:

Its position in the engine bay also wasn't helping but it was still the easiest one (top one) to get out. If it was any of the other 2 it would have had to be done from underneath:

As i later found out, the rattle from the exhaust was caused by one of the lambda sensors breaking off inside the cat.

The end result was this:

Next were the front calipers.

They are rusty and ugly, brakes are weak and the bleeders are seized so brakes can't be bled properly.

Before:

During disassembly:

After:

Bleeding:

Fitted on the car:

Moving on, rear driver side speaker grille was broken, so i replaced it with a spare:

Hand brake trim clip was broken:

So i designed and printed a repair piece:

Fitted:

Another annoying issue with the car was a faulty PDC sensor in the front bumper so, bumper off:

Crash bar taken out of the bumper to reveal the parking sensors:

New sensors going in:

Order of spare parts from audi tradition including new pdc sensor brackets as they like to brake off:

I also replaced the 2 seals for the headlight washer, as the pump was dead and the seals were leaking:

Last annoying fault was a chattering INA tensioner replaced less than 2000 miles ago:

I replaced it with another one:

And it seems happy now:

Oil level sensor was also replaced for a Hella one which had the Audi logo grinded off during production ;)

Part 10 will cover various OEM+ upgrades: