Power steering sensor

what kind of car?

Code is- power steering pressure switch performance

two of the codes are EVAP codes. The cost of the repair could be $20 or it could be up to $1200 dollars or more. It just depends on what they find. It could be as simple as a cracked hose or it could be something a little more sever like a NVLD pump or a charcoal canister.

The P0551 is a power steering switch code, i think.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

It's an issue with the pressure sensor in the power-steering lines, it needs replacement, if you're going to do this yourself, make sure you do it quickly and try to catch any fluid that might drain from the line in a clean bowl, that way you can reuse it, after installing the new sensor, refill the power-steering fluid and turn the steering wheel lock to lock 20 times, that should bleed any air from the system.

Hi:
The P0551 code is a Power Steering Switch Failure.

It is not a safety problem, most likely the pressure switch is bad.

you need the power steering performance switch. around $30 at autozone. I am not 100% sure of the name. Basically what it does is raise the idle when turning at slow speeds to keep the engine from dying on you.

It's a $10-$15 switch threaded into a power steering pressure hose just below the power steering fluid reservoir on the driver's side of the engine near the front. Look at the reservoir cap, slightly to the right (facing the front of the engine), and down a few inches. Unplug the 2 wire connector, then hold the boss the switch is screwed into with one wrench and turn the switch with another wrench. When it comes loose, plug the opening with a finger so you don't drain all the fluid and quickly screw in the new switch. 5 minute fix, then have someone clear your trouble codes.

Does the fuel line still have 55 PSI when engine warmed up? Any other codes show up?

P0551 Power Steering Pressure Sensor Circuit Range/Performance
There is a switch that senses the pressure of the hydraulic fluid which reflects how hard it is working (e.g. like when turning at low speed or when stopped). It then opens the switch (which is normally grounded) and a wire to the powertrain controller senses that and increase the idle speed accordingly so the engine doesn' falter. Here is an exchange I had earlier with another owner about it.
"The switch is located on the back side of the power steering gear. It is supposed to raise the idle speed when you are turning the wheels at low speeds when the system will require more pressure and thus otherwise drag down the idle. The wire to the switch is dark blue/light green (signal) and a black ground; and the signal wire goes to pin 45 of the powertrain control module. So you might check the connector at the switch and the connection to pin 45 of the controller, from pin 2 of the plug...
All I can add is that if you locate the two high pressure lines that run to the steering gear from the power steering pump you will find the switch right next to where those two lines connect to the gear. It no doubt just screws out and then install the new one. The manual says that you remove the electrical plug, lifting the locking tab carefully. Then it says to use a crowfoot wrench and extension to remove the old one. The steering fluid will run out so be prepared to clean catch it, and be ready to screw in the new one to minimize loss. If you catch the fluid in a clean pan you car reuse it. The torque spec with a crowfoot wrench is 12 foot pounds and you have to be careful not to exceed the limit or you may ruin the fine hydraulic threads on the steering gear and then you have a potentially expensive problem. So if you can't get a crowfoot that fits the sensor (when you buy the replacement you can see what the size it) and don't have an extension and a torque wrench you may want to let the shop do it. Make sure the electrical plug is in place with the locking tab engaging the tab on the switch. Refill the power steering reservoir. Start the engine and then turn the steering wheel from lock to lock several times to bleed the air from the system. Use only Chrysler power steering fluid if you loose some of it."
I doubt it has anything to do with the fluid, unless the code started right after that. If the wire seems OK, then the question is the switch stuck open (measure that) or is the pressure really too high when you are driving at normal speed or not even turning the wheel. That would have to measured with a gauge. Let me know what you learn, please, or have further questions. Hope this helps I know alot of info but should help you please rate thank you

po 551 is a bad power steering sensor are you sure it is the trans leaking and not the power steering po 700 is the output speed sensor on the trans either one of them is not hard to change you can do it!!!!!