Replacing Evap. canister Control Valve, Boost Sensor, and Knock Sensor?

[raja]

I took my 96 Maxima to Repair shop for Check Engine light on and they said these three parts (Evap. canister control valve, Boost sensor, and knock sensor) need to be replace. Gave me repair estimate for $900. I was just wondering how can all these three parts can go bad at the same time. Please give me some advice regarding fixing my car. Thanks
Raja

[MaxRX7]

they might good bad at the same time, but each car is different. how many miles are on the car ?

if you doubt anyone of the 3 things are the problm or the dealer is pulling your leg, you can check the codes yourself.

as for the parts you may find them in a junkyard and I think I have the Evap. canister control valve and Boost sensor, I've got to check.

[raja]

I just bought this car about a week ago and it has 80000 miles on it. I have already ordered the parts from Nissan Dealer. I will try to check the code and see if it gives me the same codes. Thanks for your reply.

[GT-R MaX]

did u go 2 the nissan dealer or a mom & pop shop?

[MaxRX7]

Originally posted by raja
I just bought this car about a week ago and it has 80000 miles on it. I have already ordered the parts from Nissan Dealer. I will try to check the code and see if it gives me the same codes. Thanks for your reply.

yeah definately

[raja]

I went to Auto Lab for code check. I checked the trouble codes yesterday and I got three codes. I didn't get a code for Boost Sensor but I did get codes for Knock sensor and Evap. canister control valve. The third code I got was for Evap. control System. I have no idea what exactly that is. You think I should replace Boost sensor even if I didn't get trouble code for that? Thanks for your reply.

[MaxRX7]

nah, don't replace it. It should be find. see what the other do first, and if you still have a problem then examine the car some more.

if the car is fine, then just reset the ecu and you are set

[Rotary Mech]

i own a early 97 max and i have the same problem.
My check engine light lit up and i need a smog.
i went to my friends garage and he pluged in a mag scanner.
my car had 3 problems: PO325-Knock senor 1 - ckt malf.
PO440-evap control - sys malf.
PO446A-evap vewt - ctrl malf.
he then cleared the codes and the light went off with out reseting the ecu. i drove the car for a couple days and the light turned back on. it goes off sometime, but most of the time remains on.

How much you spend on parts?

[raja]

I got the parts and repair shop said they are going to charge $400 just to replace the parts.
Evap. Canister control valve was for $60
Knock sensor was for $ 150.
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I think you better replace the parts. Also use premium gasoline.

[Rotary Mech]

was it hard to replace.
where is the stuff located?
can you hook it up with some instructions and tips?
did you need to reset the computer?

I always use 91 octane gas, do you think those fuel injection cleaners will help? what about octane boosters?

thanks...

[raja]

Repair shop people replaced the parts. It is not easy to replace knock sensor. I spent 2 days trying to replace it but couldn't do it. But I found somebody who replaced it for $200.

[raja]

checkout the link below. It didn't work for me but It might work for you.
I couldn't find the Evap. Canister control valve.

http://www.skippynet.com/maxima/knocksensor.htm

[raja]

More on knock sensor

http://www.automotiveforums.com/vbulletin/t42732.html

[Lewtion1]

i got the same codes before....both of the evap ones. mine was covered under warranty though. the evap stuff is for the excess fumes coming off of your fuel. it controls the levels so that it doesn't become excessive to the point of dangerous. at least this is what i found out thru research before i got it done. if you don't get them fixed, your check engine light will stay on permanently.

[raja]

I have replaced both parts and engline check light is gone. Thanks