MAS Ignition Coil Pack UF303 (E255) Replacement for Chevy/GMC/Buick H3 Colorado Trailblazer - Direct-Fit, OE-Compatible

MAS UF303 (E255) ignition coil pack is a direct-fit replacement that restores reliable spark delivery for compatible GM and related V6/L4 engines.

If your vehicle is showing misfires, hard starts, reduced power, or a check engine light related to ignition performance, a worn or failed coil pack is a common cause. The MAS UF303 (E255) coil pack is manufactured to match OE fitment and electrical connections for a long list of vehicles—Chevy Trailblazer, Colorado, Buick Rainier, GMC Canyon, Hummer H3, Envoy, Isuzu i-280, Oldsmobile, Saab and several others—covering 2.8L inline-4, 3.5L and 3.7L V5, and 4.2L straight-6 engine applications. This listing includes cross-reference part numbers for quick verification before purchase.

Which vehicles and engines will this MAS coil pack fit?

This coil pack replaces original units across many GM-based platforms and compatible Isuzu/Saab applications. Use the year/make/model selection or the interchangeable part numbers to confirm compatibility for your specific vehicle.

• Common fits: Chevy Trailblazer EXT, Colorado; GMC Canyon; Buick Rainier; Hummer H3; Oldsmobile, Saab models listed in the cross-reference.
• Engine sizes covered: L4 2.8L, L5 3.5L, L5 3.7L, L6 4.2L in applicable chassis.
• Cross-reference numbers included: UF-303, 28310, 1788390, IC051218, E255, 12568062 and others for checklist verification.

How will installing this coil pack affect drivability?

Replacing a failing coil pack with the MAS UF303 can eliminate misfires, reduce crank time, and restore consistent engine response. Proper spark reduces spark plug fouling and prevents downstream issues like catalytic converter stress and poor fuel economy.

• Reduces misfire-related rough idle and hesitation.
• Improves start-up reliability and shorter crank times.
• Helps stabilize transmission shift patterns linked to power delivery.

What should I check before and after installing the coil pack?

Compatibility and supporting components matter. Confirm the coil's part numbers against your vehicle, and inspect spark plugs and wiring to avoid overloading the new coil pack. After installation, clear codes and monitor for any recurring trouble codes or irregular engine behavior.

• Verify fit using the listed compatible part numbers and vehicle selector.
• Inspect spark plugs and ignition leads—replace worn plugs to protect the new coils.
• Clear engine codes post-install and perform a test drive to confirm issue resolution.

What warranty and quality assurances come with the MAS UF303 coil pack?

MAS includes a 1-year warranty against manufacturing defects, giving you a straightforward replacement path if the coil pack fails within the warranty window. This support helps minimize downtime and reduces the cost risk of component failure soon after purchase.

• 1-year replacement warranty—contact vendor for warranty processing.
• Built to match OE-style electrical connections and mounting points for direct-fit installation.
• Supplied cross-reference numbers to ensure correct selection for your vehicle.

Who this product is for: The MAS UF303 (E255) ignition coil pack is intended for owners, DIY mechanics, and professional technicians who need a direct-fit replacement for aging or failing ignition coils on GM family vehicles and related models. It’s best for those who want OE-style fitment, clear cross-references for parts matching, and a backed warranty for peace of mind. If your vehicle exhibits misfires, rough idle, hard starts, or erratic fuel economy and you’ve ruled out basic maintenance items, this coil pack is a practical, cost-effective replacement option.