A custom 4-2-1 extractor was installed but increased pressure from increased exhaust efficiency caused both stock mid and rear mufflers to vibrate harshly. They were replaced with custom mid and rear mufflers of stainless steel with the same dimension. The car now runs silky smooth, has a deeper exhaust note and growls like a lion past 2,500 rpm.

1. B R I N G I N G O U T T H E B E A S T:
F U L L E X H A U S T
M O D I F I C AT I O N O F T H E
P E U G E O T 4 0 7 S A L O O N
A B B A S A B D U L W A H A B

2. O F F I T G O E S !
Firstly, the ugly looking stock out-
manifold with its accommodating
bracket removed

3. N E X T T H E
M I D - M U F F L E R
G O E S
Heat shields, connecting pipe and
mid-muffler were removed to give
the exhaust specialist room to
manoeuvre, measure and design
the 4-2-1 extractor within the engine
bay.

4. C U S T O M 4 - 2 - 1
E X T R A C T O R
C O M P L L E T E D
Upon the advice of the exhaust
specialist, the extractor was
designed as 2 parts for the sake of
engine servicing practicality.

5. T I G H T
S PA C I N G
The exhaust specialist clarified
tight spacing within the engine bay
also made it more practical to have
the extractor made in 2 parts as it
was easier to be installed or
uninstalled, if need be.

6. A L L I S N O T
W E L L …
Although the extractor was properly
installed, revving the engine past
2,500 rpm caused the stock mid-
muffler to harshly vibrate as its
material could not handle the
increased exhaust efficiency. A
custom mid-muffler of stainless
steel based on the dimension of the
original version had to be
fabricated .

7. V I B R AT I O N
M I G R AT E S T O
T H E R E A R
However, the exhaust pressure now
transferred to the stock rear
muffler. It too could not handle the
increased exhaust efficiency past
2,500 rpm. A custom rear-muffler of
stainless steel based on the
dimension of the stock version now
had to be fabricated.

8. H O W D O E S I T
F E E L N O W ?
Driving the car now, the engine
feels more silky as the exhaust is
released effortlessly via the full
exhaust system. The exhaust note
is quiet below 2,000 rpm then emits
a deeper note past 2,000 rpm that
begins to growl like a lion past
2,500 rpm from the rear muffler.

9. H O W D O E S I T
S O U N D L I K E ?
CLICK HERE

10. B A C K G R O U N D
My Peugeot 407 Saloon is a Malaysian 2000cc CKD Premium model manufactured in 2011.
With the exception of the showroom model, it is the last unit of the second generation 407
series sold in Malaysia (bigger engine oil tank). The exhaust specialist told me he is aware of
a local Peugeot 407 Saloon with a custom turbo unit but to his knowledge, mine is the only
Peugeot 407 saloon with a custom 4-2-1 extractor as it is not sold off the shelf in Malaysia.