Well, if you have old plug wires, the wet wires can certainly pop this up. Many codes are "two drive cycles" meaning that if they happen once the truck thinks about it, and if it happens again, the code comes back. Causes lots of go backs to shops, where they tested it, it was OK, then owner drive it home and it pops up again next day.

That would be the 300 and 1300 misfire related codes. Many misfires are corrected by new wires and plugs.

The 1412 and 1415 are related to the SAI system testing the voltage from the front O2 sensor, the truck does all sorts of internal tests to be sure parts are still working and wild teenagers have not removed lots of parts to "hot rod" the truck, which will cause truck to fail inspection. From the RAVE see attached. It samples the volts from front O2s 80 times. If volts are low more than 55 of the samples, it turns on the code. So IMHO, yes, water could cause that. But if it does, then wiring or connector may continue to give this problem if you go wading or operate in very heavy puddle areas. Of course, splash from water is much lower pressure than 1500 PSI at the car wash.

Hopefully it will all dry out for the O2 / SAI codes.

1129 is exchanged O2 connectors, again, likely water in connector.

P0152 O2 sensor circuit high voltage (bank 2, sensor 1) Front sensor RH bank short circuit to battery supply - again could be water in connector.

One thing we can draw from this is that the underside of your truck must be clean. But that is not how the Rover gods intend it to be, go find some mud....

 

Thanks alot for the very informative reply. Believe it or not even after a lot of gunk degreaser gel and a second pressure wash the transfer case had a lot of crud on it and I had to clean it manually to find any leak. But now every thing is shiny and I crawl under it after each drive to see where it is leaking from.

The filter housing (or what ever it is called, The small part that attaches the filter to the engine) is leaking at the gasket, I see there are only few bolts to be removed so will do it next oil change. I have to find the part number for the gasket.

Since I just changed the transfer case and axle oil, will be on the watch for those too.

Could the hesitation be related to the power wash or not? I see no MAF code so this is good.
I will inspect the hoses for the SAI to make sure the pressure washe did not damage anything, should I clean the SAI valve?

I have been debating if it is a good idea to put some white shephered in engine as preventive measure. What is your take on this?

Thanks

 

The filter housing (or what ever it is called, The small part that attaches the filter to the engine) is leaking at the gasket, I see there are only few bolts to be removed so will do it next oilchange. I have to find the part number for the gasket.

Since I just changed the transfer case and axle oil, will be on the watch for those too.

Could the hesitation be related to the power wash or not? I see no MAF code so this is good.
I will inspect the hoses for the SAI to make sure the pressure wash did not damage anything, should I clean the SAI valve?

I have been debating if it is a good idea to put some white shephered in engine as preventive measure. What is your take on this?

Thanks

 

I would not use the White Shepard unless you have a leak.
I used it to stop a leak, but I would not use it otherwise.

 

After clearing the codes this morning felt some loss of power just for a second and service engine light came up again. Scanner was in the car and retrieved 4 codes P0300, P03004, P03008 and P0152. I cleared the codes and a 25 mile highway and some city driving no hesitation or any abnormal driving.
The car was parked for around 2 hours and than it was driving fine in the city. Got a ticket because missed the 25mile sign and was driving 41 (most of the street is 45 just around a mile of 25, well my mistake) any way, got back on the freeway and after about 5-10 mile the car developed very strong hesitation again. This time both at a constant speed and while letting the gas go. Much worse than yesterday and the car went into the third gear without me giving any more gas, quite a few times. after a round 10 miles it got better again and has been driving fine when got of the free way. No Service engine soon light and no codes.
I drove the car for quite abit since the power wash and I hope that every thing that was wet is now dry, but don't know what to do.

 

When you power washed the engine did you use the actual "power" wash or just a garden hose?
Washing any engine under high pressure is a big no-no.

 

Unfortunately I pressure washed every single part of the engine, "ignorance is bliss" will apply here well

 

With it being cold, and water getting into places it is not supposed to, you may have this reoccurring problem until late spring-early summer.