Hello all,

I need help. Please don't laugh. For the past 3 months, my wife tells me that when she drives the car, she sometimes get check engine light. By the time she gets home for me to extract the code, the light is off and no code are stored in the computer. When I drive the car, the light doesn't turn on (I would see if it did) although I drive the car a lot more than her, over 20,000 miles in those last 3 months.

Last weekend, she was able to get home before the light turned off. The codes I got were 0702 and 0703 "problem with the three-way Catalytic Converter".

Does someone have any idea what it could be? My Catalytic converter is about one year old. Any help would be greatly apreciated.

Thanks,
Stephane

 

I'm assuming you have the complete code breakdown as it goes on to mention, intake, sparkplugs, injectors, timing etc all though it doesn't get into a specific replacement and considering you have replaced the Cat you may want to look at what is your weakest link with the listed components and fix or repair accordingly, then reset your ECU and wait to see if the codes come back. Hope this helps some, good luck

 

0702/0703
Diagnostic Trouble Code 0702 points to a problem with the three-way Catalytic Converter.

The Cat is one of the principal components of the emissions control system. The Engine Control Module monitors the signals from the two front Oxygen Sensors and the one rear Oxygen Sensor. The signal frequency of each sensor indicates something about the condition of that sensor. A comparison of the frequency of the front sensors with the rear sensor indicates something about the condition of the Cat.

This malfunction was detected when the ratio of the signal frequency from the right bank front Oxygen Sensor to the signal frequency of the rear Oxygen Sensor exceeded a critical threshold value. This indicates that the Cat does not have enough oxygen storage capacity. The right cylinder bank is also called the rear bank. It is cylinders 1,3,5. Possible causes of this DTC include ...
- Three-way catalyst
- Exhaust tube
- Intake air leaks
- Fuel injectors
- Spark plugs
- Ignition timing