No mechanic ever told you to destroy the catalytic converter. That will land him in a courtroom in a hurry and we all know it. You're going to have to replace them before you can do any diagnostics. The first step in diagnosing this is to read the diagnostic fault codes. Only Chrysler makes that very easy for you to do yourself, however, with the catalytic converters not working, that is going to be detected by the rear oxygen sensors after those converters. The Engine Computer is going to set fault codes related to "catalytic converter efficiency". The Check Engine light will be on, so if some other problem is detected later, you'll never know it because the light is already on. A lot of those potential problems are very minor but can become really serious and expensive if ignored.
The next problem is the Engine Computer runs a lot of self tests at various times. If a fault code is already set that relates to something it uses for comparison, those tests may be suspended until the problem is fixed. That means you can develop a running problem but the test to pick that up doesn't run, so no fault code is set and you'll have no idea where to start looking.
Saturday, October 17th, 2015 AT 10:13 PM