Name: MRT Version 1 JK4 Cat-Back Jeep Wrangler 3.6L 2007-2018
Brand: MRT Engineered Performance
SKU: 90R135
Price: 1102.49 USD
Availability: InStock

// WHY THIS PART EARNS ITS SPOT

DIY installation for the backyard mechanic

T304 Stainless Steel for corrosion resistance

Engineered, designed and manufactured in the USA

// THE FULL RUNDOWN

The MRT Wrangler 3.6L Version 1 JK4 Cat-Back system has a loud, deep muscle car sound and is handcrafted in corrosion-resistant T304 Stainless Steel. Base systems include T304 polished SS 4" tips and 2.5" mandrel-bent tube. Black Ops black matte tip finish is available for an additional fee. This system is engineered for the best sound to match your Jeep and provides increased performance from the increased exhaust flow. The MRT Version 1 has an elevated sound to Get Noticed, plenty of opportunities to Feel the Performance, and packaged in a design without the excessive drone. Features: Fitment: Proposition 65 ⚠ WARNING: Cancer and Reproductive Harm https://www.P65Warnings.ca.gov

// WILL IT FIT? THE STRAIGHT ANSWER

VEHICLE	YEARS	TRIM
Jeep Wrangler	2007-2018	Unlimited Rubicon
Jeep Wrangler	2007-2018	Rubicon
Jeep Wrangler	2007-2017	Sahara
Jeep Wrangler	2007-2011	Unlimited X
Jeep Wrangler	2007-2011	X
Jeep Wrangler	2007-2018	Unlimited Sahara
Jeep Wrangler	2009	X-S
Jeep Wrangler	2010, 2012	Unlimited Mountain
Jeep Wrangler	2010	Islander
Jeep Wrangler	2010-2018	Unlimited Sport
Jeep Wrangler	2010-2018	Sport
Jeep Wrangler	2011	Unlimited 70th Anniversary
Jeep Wrangler	2011	70th Anniversary
Jeep Wrangler	2012	Unlimited
Jeep Wrangler	2012, 2015	Unlimited Altitude
Jeep Wrangler	2014	Unlimited Willys Wheeler
Jeep Wrangler	2014	Willys Wheeler
Jeep Wrangler	2015	Unlimited Hard Rock
Jeep Wrangler	2016	Unlimited 75th Anniversary
Jeep Wrangler	2016, 2018	Sport S
Jeep Wrangler	2016, 2018	Unlimited Sport S
Jeep Wrangler	2016	Unlimited Black Bear
Jeep Wrangler	2016	75th Anniversary
Jeep Wrangler	2017	Unlimited Winter Edition
Jeep Wrangler	2017	Unlimited Smoky Mountain
Jeep Wrangler	2018	Unlimited Moab
Jeep Wrangler JK	2018	Unlimited Sport
Jeep Wrangler JK	2018	Sport
Jeep Wrangler JK	2018	Unlimited Willys Wheeler
Jeep Wrangler JK	2018	Unlimited Sahara
Jeep Wrangler JK	2018	Sahara
Jeep Wrangler JK	2018	Sport S
Jeep Wrangler JK	2018	Unlimited Rubicon
Jeep Wrangler JK	2018	Unlimited Sport S
Jeep Wrangler JK	2018	Rubicon

JAP FITMENT PROMISE // If we confirm fitment for your rig and it doesn't fit, return shipping is on us. No restocking fee. That's the deal.

// GETTING IT TO YOUR GARAGE

THIS PART //

Ships UPS/FedEx ground — estimated $49.95. Additional ground items in the same order ship at reduced rates. Exact rate calculated at checkout.

REAL-COST SHIPPING

We charge what the carrier charges — no padding, no games. Ground parcels via UPS/FedEx, signature required. You see the exact number before you pay.

1-2 DAY HANDLING

Most in-stock parts leave the warehouse within 1-2 business days. Built-to-order parts show extended lead times.

LTL FREIGHT FOR THE BIG STUFF

Bumpers, hardtops, axles and full kits ship LTL truck freight (typically $400-500 per unit, plus shipping protection). Freight is charged per unit — two bumpers means two freight charges. Inspect before signing and note any damage on the delivery receipt.

30-DAY RETURNS

Unused, uninstalled parts in original packaging within 30 days. RMA required — start with a quick message. Shipping charges are non-refundable; freight returns quote at carrier rates.

FULL SHIPPING & RETURNS POLICY

// PAY YOUR WAY

CHECKING PAYMENT NETWORK…

ALL MAJOR CARDS + WALLETS

Visa, Mastercard, Amex, Discover, Apple Pay, Google Pay and Link one-tap checkout — live in our Stripe checkout right now. Card numbers never touch our servers.

BUY NOW, PAY LATER — LIVE

Klarna, Afterpay and Zip are active at checkout on eligible orders. Pick your split at payment — get the lift now, pay as you wheel. No JAP paperwork, approval happens right in checkout.

CRYPTO — LIVE AT CHECKOUT

Pay with crypto directly in our Stripe checkout — select the crypto option at payment and settle in USDC and supported coins. On-chain payment, standard order flow, same warranty.

3-D SECURE + RADAR ANTI-FRAUD

Every card payment runs Stripe Radar machine-learning fraud screening, with 3-D Secure (Visa Secure / Mastercard Identity Check) stepping in automatically when your bank requires it. Your card, verified by your bank.

PCI-DSS L1

HIGHEST CARD-SECURITY CERTIFICATION

AES-256 + TLS 1.3

ENCRYPTED IN TRANSIT & AT REST

TOKENIZED

WE NEVER SEE YOUR CARD NUMBER

Payments are processed by Stripe — the same infrastructure behind Amazon, Ford and Shopify checkouts. Dispute protection and receipt trails on every order. See our Privacy Policy.

// COVERED WHEN IT COUNTS

THIS PART //

Backed by the full MRT Engineered Performance manufacturer warranty. JAP is an authorized dealer — your warranty is valid from day one.

FULL MANUFACTURER WARRANTY

Every part ships new in the box with the manufacturer's standard warranty — terms and duration vary by brand (typically 1 year to limited lifetime on hard parts). We only sell through authorized channels, so coverage is never voided by gray-market sourcing.

WE RUN THE CLAIM WITH YOU

Warranty issue? Don't fight the manufacturer's phone tree alone. Hit our team with your order number and photos — we open the claim with the brand and stay on it until it's resolved.

WHAT WARRANTY DOESN'T COVER

Defects in materials and workmanship are covered. Trail damage, improper installation, modification, and normal wear items (bushings, pads, wear plates) generally are not — that's standard across every brand we carry.

SEPARATE FROM RETURNS

Warranty claims (defects after use) and returns (unused parts within 30 days) are different lanes. Not sure which applies? Message us first — we'll route it the fast way.

START A WARRANTY CLAIM

FITMENT	Jeep Wrangler
BRAND	MRT Engineered Performance — shop all MRT Engineered Performance parts →
PART #	90R135
SKU	90R135
CATEGORY	Exhaust Parts > Catbacks
AVAILABILITY	IN STOCK
RETURNS	30-day return window

MRT Version 1 JK4 Cat-Back Jeep Wrangler 3.6L 2007-2018