Had cat, o2 sensors and engine replaced less than a year ago, again getting p0420 code, why?

Question

Had cat and both o2 sensors replaced about a year ago, then had engine replaced. Now getting po420 code again - and many other issues since getting the engine replaced. Got car back from dealership after 12 days in shop for no start issue. Next day check engine light pops on. In the last 2 months have had it towed to dealership 4 times, transmission issues and the no start issue. Now have 240,000 miles however engine has just under 30,000 miles. Other things replaced: radiator, power steering reservoir, fuel pump, gas tank, ac components, pcm. Power steering reservoir was a real nightmare - evidently a lot of fluid was spilled on the engine, got less than a mile from dealership when engine was smoking so much I had other people asking if my car was on fire - turned around and took it back to dealership (service area was closed). Long story short - parked in front of show room with engine smoking and requested assistance. Brought my car around to service area and the sales manager arranged a ride home for me. Next day, they cleaned off the engine - according to the tech, they sprayed the engine down with water for a while in an attempt to get all the power steering fluid off. They then dropped the car off to my house - I was not comfortable driving it myself. They arrived at my house (I live approx 6 miles from the dealership) and parked my car in the driveway. The tech came to my front door and invited me out to see the car - in that short amount of time, as we walked around the corner of my garage, you could again see smoke/steam coming from my engine. Could this dousing of my engine with streams of water and then all of the time it continued to "burn off" have caused issues with my car? Main issue now, po420 code and being told I should probably replace cat again - any suggestions?

Answer 1

Hi there,

It may not mean the sensors need replacing since there are a few causes for this code. Here is a list of possible causes for this code.

P0420 CHRYSLER - Catalyst System Efficiency Bank 1

Read more: https://www.autocodes.com/p0420_chrysler.html