1991 Ford Taurus Failed Emissions

1991 FORD TAURUS
Avatar
MARYANN
  • MEMBER
  • 2 POSTS
I have a 1991 Ford Taurus SW. It recently failed the B.C. air care test. `It failed in Hydrocarbons and Oxides of Nitrogen. I had done an oil change and air filter change before the first test. After I failed I changed the o2 sensor. I almost passed the Hydrocarbons and failed the Nitrogen even worse than the first time. I'd like to know how to go about taking the error codes. I don't even know where to look or how to do it. Or if I need special equipment. Any hints on how to pass would great to. By the way the car runs good. I am totally confused and almost out of time. My insurance expires on Nov 17th. Thanks.
Nov 11, 2006 at 8:57 PM
Advertisement
Avatar
BACKYARDMECHANIC
  • ✓Experienced Mechanic
  • 337 POSTS
Maryann,
If want to read the trouble codes for your car you will need to buy a code scanner. They range in price from $50 and up depending on the make and model of the scanner. When purchasing one make sure it is for OBD II for this is the system your car uses. To use the scanner follow the instructions that come with it. A good one will have a screen that displays the directions as you use it in a step by step manner. The scanner gets connected to a plug in connection usually located under the dash on the drivers side. FYI this tool is a great help in trouble shooting your engine management system but don't be confused and think it will fix the problem. It will only lead you in the right direction. Once you know what the problem is you will still need to change the defective piece.
Good luck :) Backyardmechanic
Nov 12, 2006 at 1:29 AM
Avatar
MARYANN
  • MEMBER
  • 2 POSTS
Hi, Backyard Mechanic. I'm a little confused with your advice. Isn't the OBD II for cars from about 95 and newer? Mine is a 91. Old like me. Hope you can help. Thanks again!
Nov 14, 2006 at 5:58 PM
Avatar
BACKYARDMECHANIC
  • ✓Experienced Mechanic
  • 337 POSTS
I'am sorry didn't realize your year car . Yes you are right. Cars that are 95 and old are OBD I. Everything else is correct expect for the location of the diagnostic connector which may be under the hood or under the dash depending on make and model. You also mention you need help in pass emmissions. Here some things to look at. Make sure the motor oil is clean , of the correct grade and quailty. Second check the cooling system to see that it is running at it's best. The cooling system helps keep emmissions down. It does this by transfering the heat that the motor produces during normal combustion. The quickier the heat is transfered the lower the emmissions. One other thing is the PCV value may need changing. Hope this clears things up. :?
Nov 15, 2006 at 12:41 AM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.

Suggested Repair

Use an OBD-I code scanner; the diagnostic connector may be under the hood or under the dash. The scanner only identifies faults and does not fix them. For the emissions failure, confirm the oil is clean and the correct grade, verify the cooling system is working properly, and consider replacing the PCV valve.

Conversation Summary

The owner of a 1991 Ford Taurus wagon failed an emissions test for hydrocarbons and oxides of nitrogen after an oil and air-filter change. Replacing the oxygen sensor nearly improved hydrocarbons but made NOx worse, and the car otherwise runs well. The expert first recommended an OBD-II scanner, then corrected that a 1991 uses OBD-I and needs a compatible scanner connected under the hood or dash. For emissions, the expert suggested correct clean oil, a properly working cooling system, and a possible PCV valve replacement.

Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle