code po404 is on trying to location of egr valve

For whatever reason both the power windows and the stereo quit working at the same time. Steps taken to try and resolve the issue:

Change stereo decks
change wiring harness for stereo
changed relay for power windows
disconnected stereo and windows continue to work at random times

Please help

Truck died while at stop light. No spark to plugs and didn't have power on any wire I tested. I have checked fuses and replaced all relays.

Replace speed switch, relay, and resistor

mileage 47,760 car only 6 yrs old

just a click when i turn the key park or neutral

some saying neutral safety switch some say starter solenoid help it's cold in MN

The motor of my windshild washer works but fluid doesn't come up through the hoses. The hoses are clear, there is fluid in the tank. I can also get air into the tank. I am wondering about debris in the tank blocking suction.I am unable to drain the tank or remove the tank because I don't know how. Any suggestions or resolutions will be greatly appreciated. Thank you.

i broke my rear lights

in nutrual it acts as if it is stuck and the motor just roar

Have been fighting this issue since last Sept. Have had Cat converter heat test, exhaust system checked , fuel injector cleaning, New 02 sensors (mopar) harmonic balancer checked , Throttle body inspected, new spark plugs, even had a wire in harness replaced that dealer said looked burnt and said had a cracked fuse to sensors replaced at the same time. The Jeep runs fine at high speed but idles like a washing machine out of balance , also continues to code for 02 sensors, before wire replaced showed open circuit for 02 sensors, after wire replaced still shows open circuit for 02 sensors One shop thinks carbon build up on valves hence the injector cleaning Don't know what to do really don't want to think it could be engine also shows no misfires when tested. Does it sound like more testing of electrical is needed? Sorry for writing a book but it has become a drama...Thanks to anyone that has an idea other than tearing into my engine, no disrespect to any pro but I'm scared to trust. Wiring is pretty scary don't know of shop in Terre Haute Indiana that would be good at it..also Jeep is California Emissions also might add that second shop I went to opened harness a 2nd time and could not see where dealer had spliced a new wire ??? Jeep is 2000 has 58,700 actual miles on it and has been spoiled rotten, never any engine lights or past problems until this started..

I just replaced spark plugs, wires, coil packs ( all 3), air filter, fuel filter, pcv valve..........di you think its the module????

how do i fix this problem is there a sensor or something to be replaced

I inherited a 2000 toyota carolla that has sat for approx. the last 3 years. Was told that I might need to replace all the hoses, and was wondering the approximate cost.

Needs response ad soon as ppssible.God blesd

I am missing some of the weather stripping so I am not sure what type to purchase. When it rains hard there is a puddle on drivers side floor. I think it is comming in some where from the door.