Brz still broken but fuel codes gone

[brzcui]

Hey guys i was on the forum week ago asking about my brz. The codes for first cel are p0123, p0068, p0223. The TPS sensor is checked by the shop after and came out 100% fine. The second CEL codes are p0087,p0171. The shop suggested a new fuel pump since the fuel pressure reading is almost at 0... after confirming my car will drive fine for now i drove the car home and planned on ordering the fuel pump myself, and i haven't had any TPS codes or fuel codes this week. However, on the way home today i was downshifting from 4th to 3rd, and i stepped the gas and proceed to downshift to 3rd. It wouldn't go to gear and i felt loud vibration from the gearbox. I shifted to 3rd on the second try and soon after that downshift i smell this burnt smell in my car and CEL light and traction control light, i pulled over to read the code and it was p0068 and that code only. I haven't got any TPS codes ever since i drove it home from the first shop. I'm taking the car to the shop tmr since the dw300c came in the mail today, but what could be the cause for p0086 though? Also how could my car be running 100% fine for the whole week if my fuel pressure was gone at one point. I'm so confused with my car, it's like right when you think this car is dead you erased the code and take it to the shop it will act completely fine and when it seems completely fine it breaks and tells me it got problems. Also would i need to a retune after the fuel pump since it will be running richer ? Car has eforce supercharger tomei header perrain catback exhaust. Thank you for everyone who helped me in the past i really appreciated the community's help

[ybotspawn]

P0086 is an exhaust valve control code. That could be any of the two solenoids that control the variable timing of the exhaust cams I would think. That's likely unrelated to your fuel pump. A fuel pump raises the amount of fuel your ecu can use. You shouldn't need a retune unless your previous tune was lean. From what I read of your other post it wasn't you simply had a bad fuel pump. So finally, would it be possible to keep your one issue in one thread so people can actually follow along?

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[brzcui]

The only problem the shop found out was the fuel pump so far so thats what i brought up, i thought the tps sensor was broken so turns out wasnt. The shop has the car now and is doing fuel pump now, if anything comes up again i will make sure to mention it