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How to Register a JDM Engine in California

by Solomon Branch

JDM engines are considered custom engines. JDM stands for Japanese domestic market, which means the engine was made to be used in Japan. It may not meet California's smog check requirements, which are very strict. Making sure your automobile is equipped with the correct parts to enable it able to pass the smog check is the main concern. If that is taken care of, the registration process is the same as for any other car.

Step 1

Verify the JDM engine is the same year, or newer, as the car into which you are mounting it. If you are unsure, compare the casting number on the engine with the VIN. You can look them up online or contact the manufacturer. If unsure, check with a qualified mechanic.

Step 2

Verify that the engine control unit, wiring harness, exhaust manifold, and intake are from the U.S. domestic market by checking the part number. The exhaust manifold and intake must be the original equipment from the car or have a California Air Resources Board (CARB) sticker that matches the engine. Most parts sold in California will have this sticker; if they don't, you must contact a smog referee.

Step 3

Verify you have a non-adjustable fuel pump regulator.

Step 4

Verify you have a catalytic converter installed.

Step 5

Verify that all the smog equipment is hooked up and working properly. If you are not sure, contact a qualified mechanic.

Step 6

Contact a smog referee, who will tell you the location of the nearest inspection station. The smog referee does a more thorough inspection than the regular smog checkers and will also do a visual inspection to verify all the parts on the JDM engine and the car are correct. If you pass the inspection, you will receive a Bureau of Automotive Repair (BAR) sticker and details about your vehicle will be uploaded to the California Department of Motor Vehicles.

Contact your local California DMV office and make an appointment. The registration for a vehicle with the JDM engine is the same as that for any other vehicle after you have received the BAR sticker. The forms to use and fees will vary depending on whether you bought the car in California or out of state, and whether you are renewing your registration. You will need your title or a bill of sale to prove ownership.

Warning

  • Replacing your engine with a JDM model might change your insurance rates.

Items you will need

  • U.S. domestic market engine control unit
  • U.S. domestic market wiring harness
  • U.S. domestic market intake
  • U.S. domestic market exhaust manifold
  • Non-adjustable fuel pump regulator
  • Catalytic converter

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