Q: Code reads Cat is bad. 2nd light came on saying issue with Trans/ throttle. Can one have to do with the other? Is it worth fixing

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Check engine light is on. Shakes when idle. Mechanic said the codes from the Diagnostic lead to a bad Cat. And the shaking are bad motor mounts .We replaced a O2 sensor and the issue remained. Now a Wrench light turned on, my owners manual said its a issue detected with the Throttle body/ Transmission. Does a bad Cat lead to transmission issues? And is this car with this mileage worth fixing. Part is from Ford only so its $1400 for the Cat, $400 for the motor mounts (the shaking) . I don't know how much the transmission would be. I don't know if to Junk it or Fix it?

My car has 169000 miles.
My car has an automatic transmission.

The catalytic converter converts toxic exhaust gases into less harmful pollutants that are suitable to be expelled into the atmosphere. When the catalytic converter is clogged, this causes these gases to be backed up into the exhaust system not allowing the engine to breathe properly. When this happens, the engine is forced to work much harder to expel these gases. This often results in the engine bogging down, hesitating, shaking and causing very poor fuel economy. This should also cause a check engine light to come on as the O2 sensors should be reading the incorrect amounts of oxygen in the exhaust gases if this is your problem. It may also be possible that the throttle body may be malfunctioning causing a check engine light to come on and a code being stored. When this happens, the transmission control module may cause the car to go into limp mode resulting in the car moving only under limited power. The check engine light indicates that there is likely something wrong with the engine or transmission in your vehicle and will ususally come on in conjunction with the vehicle going into the reduced power mode. This happens when the vehicle computer detects something wrong with the engine or transmission that may potentially cause further damage or present a safety issue. It is important to have this diagnosed as soon as possible as it could range from something minor to something more serious. Unfortunately, there are many different reasons for this light to come on and the best way to diagnose is to have the vehicle hooked up to a scanner which will download the engine fault codes indicating more specifically what may be wrong. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

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