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Q: Vehicle stalls when ignited and now it will not turn on

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The issue with our vehicle is that it stalled and trembled when stopped. It got to the point where it no longer turned on. We have already changed the fuel pump and the started from a previous problem. However the problem with stalling and trembling augmented in the last month. We believed this may have been the catalytic converter and were correct, the ceramic monolith honeycomb core was completely broken and there was raw fuel inside. Catalytic converter was broken for other reasons of which we don't know the causes. A friend of our suggests that it may have something to do with the engine control module or the coil springs or ignition coils along with the spark plugs. We would like to know if you have any insights on what may be occurring. Thank you.

My car has 180000 miles.
My car has an automatic transmission.

Hello, There are a number of reasons that may cause the catalytic converter to fail. They include: O2 sensor, fuel injectors, spark plugs, EGR valve system, exhausts manifolds, vacuum hoses, and MAF sensors. I would suggest having all of these components checked to be sure they are operating correctly. Generally, when the motor is continuously running too rich (too much fuel), this will ultimately destroy the internal components to the catalytic converter by way of igniting raw fuel inside the catalytic converter. Despite the catalytic converter’s ability to withstand very high temperatures, excessively rich fuel conditions can produce enough heat to push the converter material beyond it’s limits. These types of rich fuel conditions result in higher than normal temperatures that can cause matting erosion and burn away or melt converter coatings. If temperatures are high enough, the ceramic substrate itself will melt and clog. I would suggest having an expert from YourMechanic come to our location to inspect these components on your vehicle to narrow down what may have caused this.

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