MPx 3.5" O2 Housing / Downpipe w/ Cat, 08-09 Caliber SRT-4

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Model Number: 223905-CAT

Increased Power
The Caliber SRT-4 factory downpipe is designed with primary and secondary catalytic convertors, both of which restrict exhaust flow and reduce power. The MPx 3.5" O2 Housing / Downpipe reduces these restrictions, producing a significant increase in power.

  • Gain 21 HP @ Wheels (Single, High-Flow Catalytic Convertor)
  • Gain 31 lb-ft Low RPM Torque @ Wheels
  • Quicker Turbo Spool
  • Increased Throttle Response & Acceleration

Additional Features
In addition to increased power, the MPx 3.5" O2 Housing / Downpipe offers a number of features that may not be available from the competition:

  • Direct Fit - No Cutting, Welding, or Special Tools Required
  • No CEL - Secondary O2 Sensor Defouler Prevents Check Engine Light
  • Additional Welded Bungs for Air/Fuel Ratio & 1/4 NPT Exhaust Gas Temperature Monitors
  • Light Weight - At ~9 lbs, this piece weighs less than half the factory assembly.

Quality & Consistency
MPx 3.5" O2 Housing / Downpipes are produced in large batches, using only high grade materials, by a team with a combined 130+ years of exhaust fabrication experience.

  • Stainless Steel Piping, Flanges, and Triple Layer Mesh Flex Joints
  • High-Flow, Street Legal Catalytic Convertors from Vibrant Performance
  • Steel Reinforcement Bracket designed to relieve stress caused by engine movement.
  • Fully MIG Welded with the use of production jigs to ensure consistency.

Why Choose MPx?
When deciding which performance downpipe to purchase, there can be a lot to consider. In addition to the features we've already presented, the most important thing to keep in mind is that you are making an apples to apples comparison.

While other performance downpipes may appear to be less expensive at first glance, this is often due to the fact that they are not complete assemblies. The MPx 3.5" O2 Housing / Downpipe is a single piece, complete replacement. In addition to replacing both catalytic convertors, there are no ball and socket flanges, which can leak or fail over time.

Fun facts: The OEM downpipe goes from a 4 inch inlet off the turbo, necks down to 2.7 inches before the ball socket, and then goes back to 3 inch near the end.
The MPx downpipe goes from a 4 inch, to 3.5 inch piping all the way to the rear where the flange is 3 inch. No restrictions!

$539.99
$539.99
MPx 3.5 O2 Housing / Downpipe w/ Cat, 08-09 Caliber SRT-4, Exhaust: Store Name

Ask a Product Question

  • Paolo Klug
    Hi,
    are there any known issues or problems with installation of the downpipe?
    do I have to expect any problem with a 3" exhaust system?
    where do I have to install the two lambda sensors or where do I need to place the O2 Sensor Defouler respectively?
    Thanks for your assistance
    1 Answer
    • customer service rep

      The installation of this downpipe is pretty straight forward. Just make sure to reinstall the factory support bracket to the block and you'll be fine.

      The upstream oxygen sensor is right next to the turbo, and the downstream is in the J hook all the way at the bottom. The middle sensor is for the extra oxygen sensor bung.
  • Stephen
    Does this fit a 2003 Chrysler PT Cruiser GT?
    1 Answer
    • customer service rep

      No, this Caliber downpipe will not fit a Chrysler GT Cruiser.
  • Dustin
    Hello, I currently have a Magnaflow cat back exhaust system, will there be any issues with one of these downpipes during installation or is it universal fit?
    1 Answer
    • Customer Service Rep

      This can be installed with a stock exhaust, and every other exhaust that has a factory style inlet from the downpipe.
  • Daniel
    I recently installed this downpipe and my check engine light is on now.
    1 Answer
    • Customer Service Rep

      This downpipe has been developed to have NO CHECK engine light after installation and has been in use on Caliber SRT-4's since our first prototype in 2009 with no check engine light. If you have a check engine light on after installing this downpipe, its because you installed the oxygen sensors in the wrong location. This happens way too often. You have a upstream and a downstream after the cat oxygen sensor. The upstream goes in the downpipe right next to the downpipe. The downstream oxygen sensor needs to have the wiring removed from the clip holding it in place, and then pulled out to install in the J hook style bung way at the bottom of the downpipe. The middle oxygen sensor bung is used for an extra oxygen sensor if you install an air/fuel ratio gauge later.
  • Craig
    After installing this downpipe will I need a retune?
    1 Answer
    • Customer Service Rep

      No. The Caliber SRT-4 self adjusts for any bolt on mods you have due to it having map sensors that can sense the changes in air flow. You can do air intakes, change wastegates, downpipes, exhaust, whatever you want with no tune needed. Tune is only required if you change injectors, or turbo.
  • Chris
    What grade of stainless steel are these downpipes made from and what is the wall thickness?
    1 Answer
    • Customer Service Rep

      T304 stainless steel, 14 gauge thickness.