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!