Help please. My car is Nissan Primera 1999 SR20DE engine with auto transmission. while running whether the auto transmission is engaged or not its having a dip in engine RPM accompanied with a change in the engine sound while standstill. When climbing hill and occasionally otherwise it makes pinging noise (like two metal plates hitting each other) accompanied with low power. I ran OBD II check and got the codes below.

1.P0141 02 sensor heater circuit bank 1 sensor 2

2. P0745 pressure control solenoid A

Please what is wrong with the car? Where should I check? Where actually is the pressure control solenoid?

I'm a family man and wife is pregnant and we have many journeys to embark on this month and next and this is my only car. Besides, my mechanic is at a loss regarding this fault.

Sorry for the stories. Thanks as you reply .

Update.
I informedd my second mechanic about the distributor setting as mentioned by someone. He looked at it and said its has been turned to the extreme and that the car must have been very lazy which I affirmed. He then asked me to start the car, loosen a bolt on the distributor and turned it away from the extreme gradually and GBAM! the slow running is ADJUSTED and became STABLE. The man said that the issue had been resolved.

Though still testing the car since yesterday but I haven't heard any slight pinging sound since then.