How to Find Your Engine Size Before Ordering Exhaust Parts (4 Free Ways)

Reviewed 2026-10-03. Checked against the sources listed below. This is general information, not a substitute for a mechanic's inspection.

Quick answer

The fastest reliable way is NHTSA's free VIN decoder: enter your 17-character VIN and it shows the engine size the manufacturer reported, for example "1.8" litres and 4 cylinders. You can also check the under-hood emissions label, your owner's manual or the engine cover.

Four places to find your engine size: the VIN on the dashboard, the under-hood emissions label, the owner's manual and the engine cover — The VIN is the most reliable. Decode it free at the NHTSA website.

Why engine size matters for exhaust parts

The same model can come with different engines, and each engine usually has a different exhaust layout. A 2009 Toyota Matrix, for example, was sold with a 1.8L and a 2.4L engine, and their converters are not interchangeable. Ordering by year and model alone is the most common reason exhaust parts do not fit.

4 free ways to check

NHTSA VIN decoder. Find your VIN on the driver side of the dashboard (look through the windshield), on the driver door jamb sticker, or on your registration and insurance card. Enter it at vpic.nhtsa.dot.gov/decoder. Look for "Displacement (L)" and "Engine Number of Cylinders".
Under-hood emissions label. Most vehicles have a label under the hood (often on the underside of the hood or near the radiator support) that lists the engine size in litres.
Owner's manual. The specifications section lists the engine options for your model. Match it to your VIN or label.
Engine cover or badge. Many engines have the size printed on the plastic cover, and some vehicles have a badge on the trunk or fender. Treat this as a hint only, because badges and covers can be swapped.

Also note these while you are at it

Drivetrain: front-wheel drive, rear-wheel drive, all-wheel drive or 4WD. Some exhaust parts differ by drivetrain.
Body or cab style: for trucks, regular cab, double cab and crew cab can use different exhaust lengths.
Your old part: compare the flange shape, number of bolt holes and number of oxygen sensor ports with the new part's photos.

Related AFECO parts

Every AFECO part page lists the exact years, models and engine sizes it fits. Use the vehicle selector on our home page to filter by year, make, model, engine and drivetrain.