About 2 weeks ago I took my 95 Toyota T-100 into a local Toyota dealer for an oil leak in the valve cover gaskets. They cleaned the whole top end of the engine (intake manifold removed and cleaned in ultrasonic cleaner, and used some kind of degreaser and high pressure pressure washer to clean all other top end components, front, sides, back, and bottom of engine) and had both valve cover gaskets replaced. In the process they blew off my cruise control retaining ring (my first clue, but an easy fix). After cleaning, they discovered I also had a rear main seal leak. Both leaks were very minor, but as I fastidiously keep my truck maintained I wanted them both repaired.
$1550 later, and immediately after getting the truck back I discovered a "check engine" light which I checked with my Acctron OBDII computer and it gave me a P0170 code. I had never gotten this indicator before I had any service work done.
It is now two weeks later, and last Friday my transmission would not move in 1st gear. I had to manually put it in L (low) to get it moving, and then shift up manually. Then the O/D light indicator started flashing. I immediately stopped and checked the transmission oil level, and it was dry. It took over a quart to fill it. (and I use Mobil 1 synthetic ATF, so it's not cheap). The O/D light stopped flashing, but the shifting problem remained. I decided to check the OBDII status again, and now I am getting a P0170, P0753, P0758, and a P0773 code. I have tried to look up these codes thoroughly, and they all seem to be electrical in nature... (MAF sensor. and Shift solenoids)
So, my main question is this: Do you believe (as I do) that the High Pressure pressure washing (which they did TWICE by the way) caused these electrical problems to start all showing up at the same time.. just after they did their work. I have used "Engine Brite" degreaser for many years on this engine (the truck is 16 years old with 233,000 miles) and I know better than to use a pressure washer on it. I only use a regular garden hose and my thumb, and I have NEVER had a problem or a check engine light after this maintenance. I would like a professional opinion to take back to the dealer. Thank you.