Hello all, not much has gone wrong with my 2014 1.2TSI in 11 years, but I think I will need a new exhaust back box soon. The back box is very rusty where the pipe enters it, and it makes crunchy noises if you move it. I took it to Kwik Fit for a price and they are unable to help - their suppliers cannot give them any availability, so they recommended the main dealer.

Back boxes are available on ebay for around £100 - £150, but the original system is one-piece (middle silencer and back box), which means that the pipe will have to be cut and joined to the new back box. I'm going to see if my local garage is more resourceful than Kwik Fit, but has anyone had experience (DIY or garage) of replacing the back box?

Many thanks, Jon

47 minutes ago, wellij81 said:

I think I will need a new exhaust back box soon

Wait until it fails an MOT, or starts to sound horribly loud. They can look terrible but still be operationally fine. Aftermarket units will be rather tin foil-like in comparison, I'd expect.

New genuine back box appears to be around £250 inc VAT, but would need VIN to confirm.

If it ain't broke...

I agree with @Breezy_Pete They have been 'pass & advising' the exhaust on my VW every year since 2015! This is because the original silencers have more than one layer, the outer one often peels over time leaving the inner one solid. I cut off what I could and wired it back to stop it rattling and on it goes! Jan marks 11 years of pass and advising. 😂

VOLKSWAGEN TRANSPORTER

MOT history, Check mileage recorded at test, expiry date, and test outcome, Hide

Date tested

3 April 2025

PASS

Mileage

135,417 miles

Expiry date

5 April 2026

Monitor and repair if necessary (advisories):

• exhaust corroded

• under trays fitted

• Front Sub-frame corroded but not seriously weakened under sealed (5.3.3 (b) (i))

• brake pipes/pas pipes under sealed

What are advisories?

---

---

Date tested

6 February 2015

PASS

Mileage

94,931 miles

Expiry date

5 February 2016

Advisory notice item(s)

• Nearside Rear Shock absorber has a light misting of oil (2.7.3)

• Rear registration plate deteriorated but not likely to be misread (6.3.1d)

• exhaust corroded

• Under-trays fitted obscuring some underside components

What are advisories?

---

Edited 13 September, 202513 Sep by Rheumy

Ha ha, thanks both! It's the maintenance engineer in me wanting to fix things before they break. I'm sure it will pass the MOT in 3 days time, my concern is that nothing supports the front of the back box except the incoming pipe, so when that rusts away the back box drops and digs into the road. At speed that could potentially damage other things. I'll see what the MOT garage say. Thanks for the quick replies.

The plain pipe sections have no double skin like the silencer/box does so if it's getting weak you do have to replace it because it will break.

Would almost certainly start leaking very noisily before getting so weak that it might fail completely though.

My pal has a 23 year-old Passat with the original exhaust.

My Transporter (above) exhaust will be 23 year old in Jan. I'm not changing it as long as it's not blowing.

Hi All, I thought an update on my exhaust would be useful. I've had good experiences with Kwik Fit in the past, but not this time. I explained what I thought was wrong, but they could not see the fault, they could not source the replacement back box from any of their suppliers and advised me to go to the Skoda dealer! I went to my usual independent garage for the MOT and while it was up on the ramp the broken exhaust was obvious to the eye and it failed, although the car was perfectly quiet to drive.

The garage fitted a Klarius back box for £155 all in. The part number is SK121K and is available from ebay and other suppliers for around £75. Because the original exhaust is one-piece the pipe needed to be cut to fit the back box and I didn't fancy doing that lying on the driveway so I was happy to let them do it.

On 13/09/2025 at 12:50, Breezy_Pete said:

They can look terrible but still be operationally fine.

I support this. I was having a leak from a poor connection, and when looking underneath HEY PRESTO! looked like the back box had exploded.

The one-piece is a **** piece. Was happy to have it replaced by 2 x Bosal items...