Catalytic Converter

[hr1940]

The guy that owns the shop told me to run 2 tanks of premium gas that does not contain ethanol (there is only 1 station in town that does not have ethanol in the top 2 grades) and 1 container of seafoam. I did that and there was no change. I took it back today and he would not tell me what he did but he had the car on the lift for quite a while. I think he replaced the cat -- I hope so. I took the car to AZ before taking it to him and the reading there was P0420. I also took my car to my mechanic prior to going back to the exhaust guy. and he said the oil level was exactly where it was when the changed the oil and everything checked out good. Now I will wait and see.

That all of you for your help.

Helen

 

[chris67]

If the car does not require premium fuel do not use it. Premium actually slows down theignition of the fuel and is intended for a higher compression engine that experiences a higher cylinder pressure.Don't forget that octane is/was called an anti-knock measurement. Excessive use of premium in a vehicle that does not require it will cause additional carbon deposits in the combustion chamber. The code that is given is for a convertor that is not working properly. Could be just a [censored] aftermarket but why did it need to be replaced in the first place. Engine misfires where essentially unburnt fuel enters the cat is the major reason for most failures. If the engine light is not on due to a misfire there is another way to look at the misfire counts in what is called mode 6 testing that most decent scanners are capable of. Seek a second opinion maybe at the dealer with a full explanation to them.

 

[hr1940]

Thank you for the information. The book calls for 87 octane and I will go back to that. If the check engine light comes on again I will take it to the dealer. The car is extremely quiet running. One turn of the key and it starts. I always warm the car for a minute or so before leaving the drive