Or you'l go back to the dealer and they will tell you that there is no problem and that the irregular power drop is caused by the larger than stock tires you have....even though the tires are on there all the time and the problem isn't there all the time.

Alpine and BigE,checkout the post question in the performace part of the forum I put in and see what u think, otherwise I might have to take off the 2 1/2" piping and go to the stock 2 1/4" to get some backpressure back. Thanks..Andy

Well after some thought...I'm insisting that the sensor be replaced...I can't come up with a logical reason that the 2 1/2" pipes would make the sensor retard the timing thus not allowing any supercharger assistance to the motor. Wish me luck.

Good luck! I'm going back to the dealer lat ethis month or early September and I'm not taking "There's nothing wrong, no change in acceleration at all." or "It's because you put bigger tires, thats why there's a drop in boost." as excuses. I'm printing this out and taking it with me! LINK

Good idea BigE...I'll print this also,but i don't think they will hand me excuses, the X is the 4th vehicle from the same dealer so I'll pretty much tell them to replace the sensor and it'll be done.

I have a appointment with the dealer that told me my oversize tires (32's) are the cause of my boost drop. When I called the guy on the phone asked me, "This vehicle is modified, correct?" -"Yes but nothing has been done to the engine that would cause a drop in boost." Sounds like I'm in for some more BS. :rolleyes: Any suggestions? Magnuson-Stevenson Act? Better Business Bureau? tell them, "There's nothing wrong? So if I go to the sales depatment and tell them I want to trade this in for a '07 Off Road I'll get full value, right?" Drive my X through front window?

Bige...Does your X lose its power right after the first "heat cycle"? I know mine does so I went and got a 170 degree t-stat and droppin that in and see how it does. Still haveing Nissan put the new sensor in too. A cooler motor produces more HP so I know it won't hurt.Oh and about driving it through the window....get some pics, I would love to see that! LOL

Oh and also the dealer said that your tires are the reason for the boost drop....thats bullshit anyway due to the fact that you went down 2" in your wheel size (from stock 17" to 15") then it should theoretically even everything out right?? Also definitely print out this forum and bring it with you, thats a good idea. Andy

My truck obviously doesn't like going to the dealership, the KS hasn't acted up since I called to amek the appointment yesterday. I never noticed if it does it when the engine warms up or not, I know it does a lot more and comes a lot faster in the winter months. The tires...I have 32's, that isn't much bigger than the stock tires for a SC model anyways. :rolleyes:

I'm not sure it would be a good idea bringing this to the dealership with me since I was joking around about driving thru the front door of the dealership.

I'm gettin mine done wednesday so I'll let you know how it runs...this better fix it or else it's goin up on EBAY!!LOL

O.K. so I went to the dealer to get the sensor replaced and of course the problem didn't show up, so the mechanic showed me what to look for if the knock sensor was bad. On the back left side of the S/C there is a vacum hose connected to a "bladder" that has an arm on it...when the engine is idleing the arm is halfway open and when full throttle is applied the arm is completely vertical....if the knock sensor sees a problem the arm will be all the way down therefore shutting down the S/C. And of course that didn't happen while I had it there they told me when it happens either bring the truck to them if I can or call them asap and they will change out the sensor.Also they told me that the o2 sensor could be at fault and also if I do change the t-stat to the 170 degree that I have that could also help the "detonation issue" that I'm having.....STAY TUNED THIS IS GETTIN GOOD FOLKS!!!!

Wow, I am really glad I didn't opt for the supercharged engine when I bought my Xterra 4 years ago. I still remember the dealer trying to impress me with the Supercharged model, I just didn't think the extra 30 HP was worth it.

Well so far since my trips to the dealer, the knock sensor hasen't showed up since. I guess its tempermental?? Now it runs like an animal...rips 2nd to 3rd gear upshifts again!!

My first question to the dealer. "If its a knock code and the sensors fine whats causing it? Engine coded are thrown for 2 reasons a bad sensor or a sensor detects a problem that is try to compensate for to not damaged the vehicle." Simple as that. So if there is not problem...I doubt there is, they better change the GD sensor.

Secondly, How would a colder t-stat cause detonation? detonation is caused by too high cylinder preasure or temperature or too much timing. A colder t-stat would help.

BTW how would bigger tires affect boost level?? Thats unbelievable I can see it now "Well sir you tire size changes the gear ratio so that basiclly translates through the entire PT and in turn turns the blower slower" Are they serious?!? Tell them to pull there heads out of there asses and fix your truck and then to go learn more about how different components on a vehicle relate or don't.

Exactly what I said, how can tires which are always on the vehicle affect a problem that isn't always present? They just stared at me...."Get the manager, please." ---He's not available. "Fine, tell him to call me when he feels like it or magically becomes available. Give me my keys." :rolleyes:

Hey Ryan...I took your advice and disconnected the battery for 30 mins and it seems to be running well. Put in a 170 degree t-stat (pain in the ass!!) and will be ordering the cold air intake asap. Thanks again

Andy

Glad I could be of help. Hopefully thats the end of your troubles. I would highly recommend the AEM Brute Force, easy install, looks good fits great, and most importantly it works!

I have a Airaid intake and I've been thinking of going back to stock just to see if sucking in all that hot engine air maybe contributing to the problem.

the airraid didn't come with a heat sheild?? Most of them do.

It did but the insulation strip at the top fell off and even with it, how much heat does it really keep out?

When I put in my K&N drop in filter I first took out the airbox and drilled a couple of holes in it below the filter to get as much air in I possibly could but still would like to drop in a cold air to see if theres a difference.

trust me...do it...it's not like ass kicking back in ur seat power..but its an intake...it's totally worth it.

Guys, Your knock sensor problem will return. Changing the T-stat won't change the conditions of a knock sensor.
If you are running premium gas of at least 91 octane you are doing all you can do. You have got to change the sensor. No other sensor or condition will mimic a knock sensor code and trip the sensor. Just change the sensor. Mine's going in next week. It's easy to tell if you have a bad sensor.
1. if you have a vacuum/boost gauge.It will show a 1-2 lb boost when the sensor is thrown.
2. if you have a scan gauge. It will show p0328 code.
3. sit at a stop light, turn on your A/C and then try to take off at a high rate of speed. it won't happen. It will be like dragging a 1000lb anchor.

I can't wait to use that one at the dealership, "Use a scan gauge, p0328 code will show up." Thanks!