Guys, my MoT failed on emissions - CO2 only. The Primary has been removed but still had the Secondary fitted, the plan was to leave this for emissions pass only. Yes it will fail regardless if any CAT is missing but just depends upon your MoT inspector at that time....
This guide will tell you how to remove/replace your Primary catalyst, it is purely descriptive and no photos as did not have the time as needed to get a retest done ASAP. I have included a video link below, it is in German and with this it will help, it is not difficult at all just that some parts are a slight pain but with basic tools it can be done. It took me about 3.5 hours to complete and that from start to finish (tools away etc...) and this was my first attempt at it. If you have access to car ramp then will a little more easier but if not and have a trolley jack and axel stands then it can be done.
But before you start make sure you are happy with all safety factors first, spend some time looking at what you will be doing and make sure !! So let’s start then:
1.. Remove plastic engine cover
2.. Remove windscreen wipers, scuttle panel and plastic panel (this plastic panel sits underneath the scuttle panel and is held in by 4 bolts)
3.. Remove the turbo inlet aluminium pipe and disconnect from the rubber connecting tubing. IMPORTANT, put a clean, dust free rag into the turbo inlet to protect and stop any debris going inside.
4.. Undo and remove the Turbo heat-shield 3x10mm bolts, (two at front and one at the rear), for the rear one just take your time and you need a ring spanner for this one. Then slide the heat-shield cover over the Turbo-Inlet and this will reveal the 4 exhaust bolts that secure the CAT to the turbo.
5.. You can see two bolts very easy. Then there are two more, one at the front and one at the rear, these two are not too bad to remove just take your time. For all these you will need a small socket extension bar, mine is roughly about 9ins, it was tad long as it was very close to the Air-Con pipe-work so I am going to try and find a smaller one. But anyway what I did was to remove the rear nut and the front nut in total and then just slackened off the two top nuts at the top so they can be removed later at the last stage.
6.. Unscrew and remove the top Lambda sensor of the CAT on the right-hand-side, protect the tip/sensor so I just put it inside a sandwich bag and tucked it to one side out the way.
7.. Put the car in gear, I used second gear then chock the rear wheels with wheel chock’s/bricks etc… that is in front of the rear wheels and one in front of the passenger side wheel. Using a trolley jack, raise the driver’s side and secure on axel stand. I raised it high enough for me slide under the car comfortably from the front. Once secured I slid underneath from the front and used another axel stand and roughly placed it under the car for safety on the sub frame – so basically had the trolley jack, one axel stand and another final axel stand snug fitted – just in case.
8.. Remove the driver’s side wheel, this will reveal the second Lambda sensor on the left hand side. Unscrew this and as before put sensor is a sandwich bag and secure to one side.
9.. Slide under the car, disconnect the secondary cat connection to the Primary CAT. This is on a flexible exhaust section so just place to one side, it will drop anyway so just be careful.
10.. Unbolt and remove the engine mount to the left hand side of the CAT (you will see it, aluminium in colour), it has 4 bolts. One at the bottom and two at the top, one of the top ones you can see very easy but the second one sits just below it and then finally remove the long bolt that screws through a rubber mount to the engine - you need to remove this engine mount as you will have great difficulty getting the CAT out otherwise.
11.. Securing the base of the CAT to the chassis is a plate, 2 bolts to the Chassis and 2 bolts to the bottom of the CAT - remove these as it will make it easier to remove the CAT later.
12.. Finally from the top of the engine unscrew the final two nuts that were holding the CAT onto the turbo exhaust.
13.. Slide back underneath the front of the car and remove the CAT, you will see it will be just hanging on the turbo bolts - just unhook it and slide the CAT out.
The fitting is just reverse, all I say about the Lambda sensors are this. I could not figure out how to unclip them from the plugs/connectors so when you come to refit these back then what I did was to turn the sensors anti clockwise about 6 odd turns so when you come to refit/screw them both back in then this winding will undo - so basically you’re not crossing/twisting the connecting cabling on re-insertion of the Lambda sensors.
I still had the original CAT with the compression gasket fitted, in theory it should be replaced but as long as you tighten the nuts up on the turbo-side you should be ok. The gasket connecting to the Secondary CAT was in good condition so again I reused this as well.
The video link is here below and suggest you just watch it first then read through the above, if you understand German then your laughing… He didn’t remove the scuttle panel, also he removed one of the turbo nuts from below - I found what I did more easier, it may have took a little longer but then I saved a few scraped knuckles etc…