I have a 97 maxima with 97k miles on it. The other day it started shifting hard between 1st and 2nd gear. I got a DTC printout and it had two items...

LINE PRESSURE S/V [P0745] 0 times

H02S2 (B1) [P0136] 1 times

What needs fixing to stop this hard shift? How much will it cost approx.? Thanks!

Second code (p0135) is for an oxygen sensor. Not related to the shift problem, but it might be costing you fuel economy and could cause you to fail an emissions test. Here's a thread covering that specific sensor/code:zerothread/185155

The first code is for a transmission valvebody solenoid, and is what's causing the hard shift. The line pressure solenoid regulates fluid pressure for actuating shifts.It's probably a bad solenoid, or maybe a harness or connector problem. Nothing horribly serious, and I believe the solenoid can be replaced with the car on a lift (no need to drop the trans).If you go to page 93 here you can find more info on the problem. If you're familiar with a multimeter, you can try the diagnostic procedure listed there in your driveway.

Did you ever fix the code p0745? where is it located?

Did you ever fix the code p0745? where is it located?