Check engine light is on. Just got my Prius back together yesterday after water pump/thermostat/pcv/egr/cooler/manifold service. Was very careful to torque it all, went over each connection several times. I didn't put the cowling back on yet, will do so in the morning. I did connect the wiper motor to avoid an error code. Ran for a bit in mainentance mode, refilled with about a gallon and a half of antifreeze fluid. Tomorrow will get the car completely ready to drive. It sat for a few weeks but started up easily and battery is mostly charged. ODB scanner says "MANFOLD ABSOLUTE PRESSURE / BAROMETRIC PRESSURE CIRCUIT HIGH. Dr. Prius cannot seem to connect to this scanner. Any ideas, I'd be happy to listen. My plan is to get it out for a drive and see if the symptoms resolve.
A bit more background here. I did buy a new exhaust manifold off ebay. It was reviewed well by others but it is a cheap version. Forgot what I paid. I will clean the old manifold tomorrow and see if that fixes it. Also got a new EGR valve online from a Toyota dealer on a close out. A bit over $100 dollars. I can clean the old one as well. Wasn't getting this code before. Will also check MAP sensor to see if anything obvious is wrong. I suppose the first thing to do is just clean the MAP sensor and hope the code goes away . Edit: I did order a new MAP sensor. It was cheap enough. My suspicion is the manifold. Second time around should be a lot quicker. Of course, the map sensor bolt did break off in the manifold, so there's that . My biggest concern of "too much pressure" is blowing a head gasket.
Got down to the map sensor and went to remove it, but noticed it slid out easily. Apparently, I didn't connect it properly. Clicked it, disconnected the battery/waited 10 minutes, and no code on the start. Now to put the cowling back on and take this sucker for a test drive . No error codes, no triangle of death. Thanks to Merv and NutsAboutBolts and all the guys on PriusChat! Now I do know it is sacrilege, but I did put in a 1/2 dose of the low dose Kseal, which was 2 oz total. Hoping to seal any very tiny issues that could be staring with my head gasket. 205k, hoping to get to 300k before I replace the head gasket or the motor. Had I not run into so many broken bolts, this would have been a 2 or 3 day job for me. I'm not a pro, I haven't got the greatest tools. All in all, a great learning experience. Just hoping that's the end of it and I can drive for a few months without issues. My advice to others is if you don't have an extra car and can afford to be down for a while, pay a shop to do this.
Looks like the OP might have things sorted, but just for other readers who happen by, $0738 is not a trouble code. Trouble codes all start with a letter P, C, B, or U. The $0738 would be the CAN address of an ECU that has a trouble code. Not completely uninteresting, but tells you much less than an actual trouble code.
The bane of this job was the 6 mm bolts. I had about 6 of them snap on me, only able to get two out and the rest I had to drill. The ones I got out broke right at the rusted nut but were easily turned by pliers. The ones that broke at the base, impossible for me to extract. Very important for first timers to realize that these bolts can be very problematic. Wish I had knows this when I started. Had no issues at all with 8mm.
If you will entertain a grumble: by my count this is the seventh thread you've started, on essentially the same topic.
It's important, in any case, for readers to recognize what part of the readout on an OBD scanner is a trouble code, and what part of the readout is not a trouble code.
We're all of us that close (holds finger-and-thumb tightly pressed together) to an existential crisis, in this thin veneer we call reality. That's my navel-gazing quota for today.
