MPx Downpipe w/ Cat, 03-05 Neon SRT-4

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Model Number: 220914-CAT
Have a MPx exhaust on your 2003-2005 Dodge SRT-4 and want to buy a replacement downpipe ?

We are now offering the MPx downpipes sold seperately from our exhausts in this listing. This is the same MPx downpipe we package with our complete exhausts and these are made with 304 stainless steel.

This listing is for the downpipe with cat for use ONLY with the 2003-2005 Dodge SRT-4 MPx exhaust system.

We offer an option with this downpipe to have an additional oxygen sensor bung welded into the downpipe to make installation of a air/fuel ratio gauge easier. If you dont plan on adding a air/fuel ratio gauge soon, or dont have one installed in your car now, theres no need for this option.

Please note, this does not come with gaskets, so please purchase gaskets in our seperate part listing if you need new gaskets)

This downpipe is only designed to work with MPx exhausts, and if you have a stock exhaust system, or any other brand of exhaust, this will not bolt on. You will need to have a local muffler shop cut the flange off, and weld/modify this to work with whatever you have.


Additional Options

MPx 3.0" 3-Bolt Exhaust Gasket

Model Number: 220913-GASKET
Do you need a replacement 3-Bolt Exhaust Gasket for your MPx Exhaust Dual or Side Exit Exhaust? We carry spares of the Read more

MPx 3.0" 4-Bolt Exhaust / O2 Housing Gasket

Model Number: 220915-GASKET
Do you need a replacement 4-Bolt O2 Housing Gasket for your 03-05 Neon SRT-4 or 03-07 PT Cruiser GT? We offer Read more

MPx Downpipe w/ Cat, 03-05 Neon SRT-4, Exhaust: Store Name

Ask a Product Question

  • John
    Please advise what size is the Cat and piping. Also will this allow my car to pass the E test and with the engine in stock configuration and operating tip top?

    1 Answer
    • Modern Performance

      Both the piping and the catalytic converter are 3 inch in size. We have no idea what an E test is but are confident you'll pass the exhaust emissions test in every state except for California which has super strict CARB laws.
  • Skeet
    Yes I was wondering if I have 500hp will the cat effect my hp numbers/performance compared to the down pipe without the cat ?
    1 Answer
    • Modern Performance

      The catted downpipe will affect you only in top end power. It really all depends on your tune, otherwise you see a slight effect on performance.
  • john
    Ohio emission testing Wants me to prove the cat in mpx down pipe passes EPA approval for my customer. we put this complete stainless exhaust sys on 5yrs ago. computer readiness status all clear. but at this point they consider it tampered with and need to show epa approval. previous years we had no problem. im lost ...what to do?????????
    1 Answer
    • Modern Performance

      There is no such thing as EPA approval. The only approval there is for the US market is CARB testing which is only good for California vehicles.
  • Balvino
    Can you ship this to California?
    1 Answer
    • Modern Performance

      Yes, of course. We ship daily across USA, Canada and even internationally.
  • Brandon
    Is the cat on the MPx downpipe a high flo cat?
    1 Answer
    • customer service rep

      Yes the MPx downpipe uses a 200 cell, high flow catalytic convertor for maximum flow, but yet allows for emission tests to be passed.
  • Jeremy
    If I choose the additional bung, where is this bung placed? Before the cat? Before the flex joint?
    1 Answer
    • customer service rep

      If you choose the additional bung, its placed after the flex joint, but before the catalytic converter.
  • Alex
    Is this downpipe compatible with the stock O2 housing or is the MPx O2 housing required?
    1 Answer
    • Customer Service Rep

      This downpipe will work with the stock 02 housing, the MPx 02 housing and any other stock replacement SRT-4 o2 housing.
  • Dustin
    Will this downpipe bolt directly up to a 3" AGP o2 housing? The connections look the same. If yes, will your full mpx exhaust system work with a 3" AGP o2 housing?
    1 Answer
    • Customer Service Rep

      The AGP o2 housing on their turbo kits are designed with the same 4 bolt style flange as factory. Its also in the same location so you can use any downpipe made to work on the Neon SRT-4. Yes, this one works as well.
  • Brandon Barrett
    Is it possible to get this with a 2 bolt flange instead of a 3 bolt to match up to a B&B exhaust?
    1 Answer
    • Customer Service Rep

      No, Im sorry we are not offering customization of this piece. This downpipe was made exclusively to be used with the MPx exhaust. You can modify it to your liking though or to match whatever exhaust/custom setup you want though.