Check Engine Light on?

Firstly, check the coolant and oil, and transmission fluid, make sure they are at the correct levels, we should runt he codes this guide will show you how

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.

Retrieve the trouble codes that the engine light has stored. Most part stores do this free of charge. Let me know what code(s) you retrieve. This will pinpoint the culprit much quicker.

This can be an o2 sensor or maybe low fuel pressure due to a bad pump or clogged filter, etc. Auto parts rent gauge for this.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Did you get it figured out? I need to know the exact code that your aunt got.

P0141 OBD-II Trouble Code Technical Description
O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)

What does that mean?

This code means that the heated circuit in the oxygen sensor on bank 2 decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0141. See also: P0135 (Bank 1, Sensor 1).

Symptoms

You will likely notice poor fuel economy the illumination of the Check Engine Light.

Causes

A code P0141 may mean that one or more of the following has happened:

* open or short to ground in the wiring harness
* O2 heater circuit wiring high resistance
* O2 heater element resistance is high
* Internal short or open in the heater element

Note: Typically a failed catalytic converter does not cause this code. You're more likely to see a P0420 code for a failed converter.

Possible Solutions

* Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)
* Repair short or open or high resistance in wiring harness or harness connectors

Bank 1 sensor 2 is the O2 sensor after the cat connected to cylinder #1. Based on the description and the work that you did, it very possible that when you re-installed the exhaust pipe, you either forgot to connect the O2 sensor to the connector, or you pulled the connector too far and it broke, so no continuity, or it just so happened that the sensor went bad. I believe your case is either scenario 1 or 2, unlikely 3. If after to check, you need to replace the sensor, make sure that you get the sensor for after the cat for bank 1 (cylinder 1). They look identical, but they are not the same.

What do you have for codes?
Which fuse that keep on burning?
Gas cap will not cause a fuse to blow
have to check wiring harness check around the exhaust manifold
let me know

1st step should be checking o2 sensors wiring if touching the exhaust system
look a melted wire
Good luck

What do they mean lost a cylinder? Something sounds a little funny, especially with an extended warranty and a maintained car with only 65,000 miles.

What codes were in there?

Get a second opinion, regardless of the warranty.

Check engine light:

Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to turn on-This is your starting point of diagnosis, finding out what's going on.

Wife has same rig, 'cept it's 2WD. If the Check engine light is on that means the computer is throwing out a Code! To get a accurate diagnosis, you need to have the codes read. You can get this done for FREE at Advance Auto, Autozone, and some other popular parts stores. Do not take this to heart 'till you get it coded.I suspect you are running "Rich" not "Lean" due to ----"A SENSOR" making your rig remain/ or go into "OPEN LOOP" (Open loop is your car running off of preset values programmed into the computer. Just to make it run, but not to its full potential) Computer cars all do this, when you crank-up, the O2 Sensors (others too) are cold and cannot function until they get warmed up and are able to send REAL WORLD DATA to the computer, so it can efficiently adjust the fuel burn. When these sensors do COME ON LINE, the vehicle goes into CLOSED LOOP and Ever Changing, Real Time Data is fed into the computer to make the fuel burn as good as possible. My suspicions are that you have a O2 sensor problem. It might be that one has gone bad, or maybe the catalytic converter replacement left one disconnected or broken. There are several on your car. Insure that if the "Coding" leads you to a O2 sensor problem. Find out which one, as these puppies are not real cheap items, before you replace all 3 unnecessarily! The parts store guys are generally able to explain what the codes mean, and what you may need to do. Let me know how it goes--The Medic___________thats Mama's Rig sorta behind a "Real Vehicle" (mine)