Auto Transmission stuck in gear 2001 Tacoma (Helpful Info inside)

Hey guys just wanted to make a post to hopefully help someone out in the future. I was working on a 2001 Tacoma 3.4 4x4 Auto with 175k Miles. Did valve cover gasket and full tune up took truck for a ride drove great.
Then decided to pressure wash engine bay while running to get all that old grime off. Engine came out great truck was running strong. 2 days later the truck would not shift out of 1st gear.
Now something I wanna mention is before any of this I always had that typical cold start delayed shift from 1st to 2nd. Well Double checked all connections. No issues, no codes coming from ECU. Next dropped the pan and checked filter and solenoids again all tested fine. Fluid on the truck was great looking so I was skeptical about a random failure as it shifted fine before. After 2-3 days I decided to give in and pay a local shop.
Well $500 Later I come to find out it was simply a faulty TPS. Now I had no codes and even was watching data that I could view using torque datalogger nothing ever pointed to TPS. While the bill was high I wasn't upset as I understood the shop had to trouble shoot. I spoke with the 2nd tech who took over troubleshooting and he explained to me that he wished he started on it as he could have saved me about $250 in diagnosis. According to him a failing TPS is very common with the 98-01 Tacomas with a 3.4 he said that delayed shift when cold is a sign its starting. Also that it will still show ok on a datalogger unless you have one that reads volts vs TPS %. He piggybacked wires to the plug and taped the meter to the window and while doing a drive around the shop saw the voltage randomly pegging making the truck think It needed to be in 1st gear as if I was passing someone or holding the pedal wide open. He said the pressure washing may have caused it but if I had the delayed shifting that was an early tell tale sign. I researched but found nothing about this online. I saw 2-3 threads where folks mentioned the transmission would get stuck in a gear or not shift after washing the engine bay or just randomly start acting up after parking it. So moral of the story if your trans was fine and now its shifting rough, skipping gears, stuck in a gear etc. Before going crazy measure voltage at the TPS per the manual if in doubt it may even be worth buying a $40 replacement TPS before digging into the transmission. Hopefully this helps someone in the future avoid a costly simple repair.