BPT Value 94Q45

[Ted]

This morning when I start the car, the engine at idel shakes a little bit. When I start to drive, the engine light lite up and the engine is rough. I recently have a mechanic changed the O2 sensors, and the EGR valve within the last 3 months. The car was running very smoothly until now. I hear a little knocking when I listen to the engine. When I pull the hose under the BPT valve and block it, the knocking noise decrease. Could it be the BPT valve? Or is the O2 acting up again?Please advise.

Thank you.

TED

[911/Q45]

Check the ECU for codes, sounds like a bad injector.

[Ted]

911/Q45

Wow - Your diagnosis is dead on. I brought the car to Frontier Infiniti (San Jose) and their diagnosis: injector #5 failed, and knock sensor failed. The cost is going to be $1600 for parts and labor

So I decide to buy the parts and try to fix it own my own. I know where the injectors are, but where is the knock sensor? Does anyone has a picture or diagram?

This infiniti community is always a great help and source of information.

Ted

[pito11213]

Both knock sensors are located below the plenum. When you remove the plenum they are located towards the back in the valley.

The general consensus is though since you will be in there to change out the hoses since you dont want to have to go back and forth in there.

Also since when you remove the plenum some hoses may crack on you giving you much more headache.

[maxnix]

Yeah, for $1.6K, you can do some serious preventative maintenance and ensure and extend the life expectancy of your car. Look for previous links for FSM, TSB and member's posts on plenum removal.

[elwesso]

Checkout my plenum writeup on Q45.org...

Youll want to replace both knock sensors as well as the harness...