Hi, I own a 1998 Honda Accord with about 85,000 miles on it. The check engine light came on so I took it to the dealer for diagnostics. They told me I needed a new 3rd clutch pressure switch and catalytic converter (P1739 and P0420). I had the pressure switch replaced and the light went out. It has not come back on. I had a catalytic converter put in with a local mechanic about 1.5 years ago. Do I need to replace it again? Could there be hazardous fumes entering the passenger car if I do not have it replace?
If you need a new converter, that light will come back on.
Your Accord shouldn’t have needed a converter a year and a half ago, and it shouldn’t need one now.
P0420 means the converter is working below threshold, but that does NOT mean the catalytic converter needs to be replaced.
This code is often caused by an oxygen sensor that is beginning to fail, causing the catalytic converter to work at less than optimum.
When this code comes up there are a series of diagnostic tests that will determine which component is faulty. Quite often it’s not the catalytic converter, but a much less expensive component, such as an O2 sensor.
Too many “mechanics” replace the converter (highly profitable) rather than do the testing to determine the true reason for the code (less profitable). Find someone who will do the necessary testing instead of throwing parts at the problem.
And, no, there won’t be any hazardous fumes if you don’t replace the cat.
After about 300 miles of driving, while I was going full speed on the highway, the check engine light came back on. I took the car to a local mechanic who was highly recommended. He said I need a new catalytic converter. He said the one I had installed 1.5 years ago was very poor quality. Any thoughts on this?
Still highly unusual. On a well maintained car, the coverter will vitually last the life of the car. I have never replaced one, not even on a 19 year old car with 320,000 miles on it.
There must be somthing wrong in the engine with respect to air/fuel mixtiure or condition of spark plugs to really cause a converter to fail. Unless it is damaged from the outside.
The original one might have been damaged from the outside. For years, I parked the car on the street (which in the city often has alot of snow etc).
i have a code 1739 on the same year accord and think that the swich needs to be replaced. how much did you pay for that.