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2001 Jeep Wrangler 4.0L 6-Cylinder P0303 Code Only When Engine is Hot - Fix with Exhaust Manifold Shield

Model: Wrangler Fault Code: P0303 Posted: 2011-08-18 08:39

I'm seeking help with a recurring issue on my 2001 Jeep Wrangler 4.0L 6-cylinder manual transmission model, currently at around 71,000 miles. The vehicle consistently throws Diagnostic Trouble Code P0303 when the engine reaches operating temperature—typically during highway driving or after refueling. After stopping and restarting the engine, I experience a brief stumble or rough idle for several seconds before returning to normal operation. The check engine light and P0303 code remain illuminated even after restart. This issue has been present for approximately 1.5 to 2 years. I've already replaced both the #3 spark plug and the corresponding coil pack, but the problem persists. Any insights or solutions would be greatly appreciated. Thanks, Tammy

Related fault codes

P0303

Comments (2)

Anonymous 2011-08-18 18:43

In some cases, excessive heat from the exhaust manifold can cause fuel injectors to overheat and malfunction. Chrysler issued a Technical Service Bulletin (TSB) recommending the installation of an exhaust shield around the fuel injectors to reduce thermal exposure. As a cost-effective DIY solution, you could fabricate a protective shield using cable insulation material similar to what is shown in the TSB before pursuing more extensive repairs.

Anonymous 2011-09-02 14:06

Thanks Jeff. I tried taking it to a dealership for the TSB fix, but they were not responsive and instead suggested I 'bring it in'—which typically means they'd charge hundreds of dollars just to inspect it. Since that wasn't feasible, I researched the TSB independently and created a shield using cable insulation material that closely matches the design shown in the bulletin. It's been working well so far. Tammy