DoubleO7

Hello,

My check engine light has been on for quite some time and
first it indicated that my rear O2 sensor was bad. So I
replaced it myself. After which, the light stayed on even
after trying the reset. I checked the values again and found
my knock sensor and coolant senser are in trouble. I'm not
quite sure where they are located and how to check them. I
need help in location, diagnostics and installation can anyone
help?

I would also like to thank the creators and members of this forum for I have found a lot of useful information to help me out.

Can anyone also recommend the best auto repair book to buy?
I have heard a few people mention Haynes.

Thanks for all your help in Advance,
B

Daniel B. Martin

The aftermarket manuals are a good choice for most home mechanics.
Haynes is better than Chilton. For a detailed comparison of manuals, see http://vbxmaxima.8m.com/manualcompare.html

Daniel B. Martin

On the 4th Generation Maxima engine the Engine Coolant Temperature Sensor is located in the water outlet tube close to the engine end of the upper radiator hose. There are two sensors in that area. The one nearest the hose is for the dashboard temperature gauge. The ECTS, the one you're interested in, is right next to the the gauge sending unit. There is a good picture of these sensors in the Haynes repair manual on page 3-7.

The ECTS is reasonably accessible. You will have to move some hoses and wires which lie immediately above it. Disconnect the electrical connector and use a 19mm deep socket, an extension bar, and a ratchet.

Daniel B. Martin

Raise the hood. View the engine from the driver's fender. Look into the deep valley between the cylinder banks and below the intake manifold. Identify the KS as a black item fastened to the block by a single vertical bolt with a 14mm hex head. A wire harness wrapped in black leads toward you, out of the valley. That is the KS sub-harness.

The manual says you have to remove the intake manifold to replace the KS. However, I think that a person with good dexterity and a 14mm ratcheting box wrench could replace the KS without disturbing the manifold.

I suggest you replace the ECTS, reset the Engine Control Module, and drive normally for a week. Then do another ECM Diagnostic Trouble Code readout. Perhaps replacing the one sensor will clear both codes.

The KS is fairly expensive. If you always fuel with 91 AKI (or better) you may consider ignoring the DTC 0304.

knight71

go to motorvate.ca...lots of DIY info

ChrisA

I also had codes for both knock sensor and temp sensor. I reset the computer and the knock sensor went away leaving only the temp sensor. I changed the temp sensor this weekend, it was $29 at Nissan. As long as you move some stuff out of the way its not too hard. I definately had the air intake that rests on top of the radiator off as well as maybe some other hoses. I could not get any socket over it, at least with the ratchet attached due to something that was in the way (forget what). I ended up getting an open wrench over it which only worked directly from the side with the back of the wrench going towards the firewall. Could only do a 1/4 turn at a time but it came off no problem. A little slow due to the corrosion. The new one goes on easy. My radiator fan had been kicking on for no reason before changing but that has now stopped. I also did a lot of other things while it was all apart..cleaned tb, fuel filter, plugs etc which you may want to do if you need them done anyway.

Here's a couple pics. 1st is of the new temp sensor after installing and the second is of the old sensor:

www.mywirelessdeals.com/tempsensor1.jpg
www.mywirelessdeals.com/tempsensor2.jpg

Chris

ChrisA

After looking at the old one again I wonder if I had just removed it and sanded the corrosion off it if it would have still worked and saved $29. It's worth the money to me to know its fixed though.

Chris