P0420 on Honda Accord 2000 EX 4dr?

Question

There was dust in my gas tank and I got check engine light. 3 Cylinders were mis firing. After the tank was cleaned I was asked to drive for 20-40 miles at 60mph(with fuel injector cleaner)to clear any clog in fuel injectors. It did not help. Then got the injectors replaced. It ran very good for a day. Then I got Check Engine Light and OBD Code P0420. My mechanic reset it and asked me to see him if it comes again. He also that old hondas can get this in winters for no reason.

I don't see any difference in my car performance. I just get check engine light.

Is it safe to drive the car?
What coluld be the problem with the car?
Is it true that some old hondas get his problem in winters?
Can this be because I drove for 40 miles with bad fuel injectors? At that time cylinders still misfiring.

It has 91000 miles on it

Answer 1

What you are experiencing is a catalytic converter efficiency problem. Just clearing the code won't make this one go away. This is usally caused by a rich running ciondition over a period of time, or an air leak in front of the converter. The proper way to check this condition is to get the vehicle in the air and have someone run the vehicle above 2500 rpm for atleast 3 minutes. While it is still reved up, a laser tempeture probe should be shot at the pipe before and after the cat. You will need pre and post temp readings. The temp in should be MUCH less than the temp out. IE: 425 deg in, 645 deg out. Anything within 100 degrees is bad. Your cat is like a reactor. It needs to be hot and litterly burn inside. That is its job. Driving with a constant missfire, or leaky exhaust pre-cat will distroy the cat.

I would reccommend you take it to a qualified professional. DO NOT ATTEMPT TO TAKE TEMP READINGS WITH A NORMAL THERMOMETER. YOU WILL BE BURNT!!!

Good luck.

Answer 2

The code P0420 means that Catalyst System Efficiency Below Threshold. Welcome to our website www.diyobd2.fr and get the best product and service.and i believe you will be satisfied.