Your engine runs at around 200°F so your climate doesn’t change the oil recommendation. Neither does age. Stick with the recommended oil

Doubltful that it’s caused by the oxygen sensor. Most common cause of reduced MPG is worn spark plugs. And to answer your question, no, you don’t need to replace the downstream because it has nothing to do with calculating air/fuel mixtures. Its only job is to monitor the cat performance.

Looks like a factory service manual. That’s what FSM means

Rotors don’t warp. That’s a myth. There isn’t a street vehicle in existence that can produce enough heat to warp cast iron. But disc thickness variation caused by lateral runout is what most people mistake as warped rotors. The most common cause of lateral runout is not cleaning rust off the wheel hubs and not using a torque wrench to tighten lug nuts. Anything that prevents the rotor from spinning perfectly parallel with the hub will cause lateral runout wobble and that causes opposite side rotor wear or opposite side brake material buildup. Either one causes pedal pulsation

The variable valve timing system (VVT) on an engine operates using oil pressure. If the oil is oil or has any sludge, that can cause the VVT system to not run properly and set a trouble code. Many times, you can fix that by cleaning the filter screens on the mechanisms and changing the oil. In fact, if the shop suspects the oil is the cause, changing it is the recommended procedure.

So ASK the shop if that’s whey they changed the oil before you go off the deep end and start accusing them of screwing you.

OEM, Moog, Beck Arnley, or TRW

Locate the heater box under the dash and look for a black rubber tube that comes out of the bottom of the heater box and heads down through the floor. That’s your drain. Lay a towel down and remove the rubber drain from the heater box. Be prepared for a flood of gooky water.

Any advise other than scanning?

No, because scanning for the trouble code is ALWAYS the first step in diagnosing a problem like this

The oil cooler/filter assembly on these chrylser products are garbage. They have almost a 100% failure rate. Look at them wrong and they leak. The dealer blame the oil change shops for overtightening the oil cap, but even if tightened with a torque wrench, these units still fail. It’s a horrible design and the dealers are looking to blame anybody but Chrysler. This really should be a recall item

Aquapel is a hydrophobic glass treatment product. You can buy it online. Last for about a year.

I would check the wiring harness and connector at or near the alternator. Sounds like an intermittent open condition.

Depends on the type of battery and the vehicle. If your vehicle has an AGM battery that’s the going rate. Also, if the battery is hidden, it can take longer than a battery that sits out in the open. Lastly, depending on the vehicle, some computers need to be programmed to let it know that it has a new battery. Failure to do that can destroy the new battery.

Perhaps if you had followed the rules and listed year, make, model, you could have gotten a more exact answer.

Yup. New caliper time

First, you service manager never should have given you this job without some help. He’s a moron. You don’t take an inexperienced tech, hand them a huge job without backup and then wonder how it’s at 60-hours. If you want to stay in this business, you need to do two things: 1) learn how to say no to jobs you’re not trained on and 2) find a new place to work where the boss understands the concept of helping a tech become successful. A good boss pairs you with a more experienced tech to help you learn and become more productive.

Automotive stethoscope or a piece of garden hose. Works every time

Sounds like a caliper is not releasing. Since you’ve replaced calipers, the only things left are bad flex hose or a clogged ABS valve in the hydraulic unit

You’re making the assumption that there was nothing wrong with the engine and the noise is only from the differential and that the dealer totally misdiagnosed this. Cuz it sounds like the max on your warranty is $5K and they’ve already paid that.

No

No, it’s not good for your battery or your alternator, and there’s always a very small risk that it can fry the computers in your car due to voltage spikes when hooking up and detaching the jumper cables. That doesn’t happen very often, but it’s also not a no-risk situation. Tell them to get it fixed or take full responsibility for anything that happens to your vehicle.

Go to a locally owned muffler shop. They do this all day long and will be a lot less than a mechanical shop