You are here:

Toyota Repair/93 Toyota V-6 P.U.


I own a well maintained 93 Toyota Pick Up V-6 with 144k on it. After market cat 40k ago. I run mid grade gas. The truck passed emissions tests prior to 2013, no problem. Since then California changed the emissions standards. I have not re-placed any of the emissions parts since I have owned the truck except the cat at 105k.I pass 25mph test but fail 15 mph HC at 125 max is 92. Suggestions ? Thanks.

Higher than allowed HC levels are usually due to incomplete combustion to some degree, that is, too much unburned fuel is coming out of the exhaust, it's not that far over so maybe doing a tune up, new plugs ,wires etc and making sure the timing is correct at about 8 degrees advanced may help pass it. Also be sure the engine temperature goes up to normal when it's ready to be tested, put a can of gas treatment in the tank before testing it and drive it at higher speeds, freeway for about 20 minutes, autoparts stores have some additives that claim "guaranteed to pass" or your money back, give that a try, like I said it's not that far out of line, hope this helps.  

Toyota Repair

All Answers

Answers by Expert:

Ask Experts


Ted Ritter


I have more than 28 years experience as toyota technician, I will be able to answer most questions related to the Toyota product line up to the present year models,I am located in the US but welcome questions from other regions of the world. When asking a question please provide specific information: year,model, engine,transmission information. Provide as much information as possible including a brief repair history if possible. I have been a volunteer here for more ten years an have answered over 16,000 questions helping Toyota owners with their problems and save thousands of dollars without any compensation, some of my answers are published on many other websites including google and various automotive forums. DONATIONS ARE VERY MUCH APPRECIATED, IF YOU HAVE RECIEVED HELPFUL INFORMATION PLEASE MAKE A DONATION. AS OF TODAY (JULY 22, 2014) ALL REQUESTED GRAPHICS, ILLUSTRATIONS, DIAGRAMS, PHOTOS, WILL REQUIRE THE MINUMUM DONATION UP FRONT.


Toyota technician since 1979,expert in electrical systems,OBD systems,engine repair, driveability problems,EFI systems,ASE certified,Toyota master technician.
Certified Hybrid Vehicle technician.

Toyota master technician, ASE certified in eight catagories, Hybrid vehicle certified. Toyota technical training: Engine Automatic transmission Manual transmission Drivetrain Electrical systems Brakes and chassis Air conditioning Engine performance and diagnostics Hybrid systems

©2017 All rights reserved.