[garywayne123]

could the p00420 be causeing my knock sensor code??????? hope this isnt the end for my motor... seems like this 2.5 could be a great engine

 

[i68k]

any misfire, engine shaking, bad gas, could cause a knock. but your p0326 is circuit/voltage related.

still not sure on your year/model. if you have 02-03 qr25, this is a common problem, many people just relocate the knock sensor, but its possible you may need to reground it, or replace it.

this knock sensor is not directly affected by your p0420 cat code, if fact, if you have a p0420 your ecu should richen the afr causing leaving a knock less likely to occur. if you have all these voltage related codes, i would question your battery, battery terminal tightness, ground contact, voltage motor on&off, just in case youre getting these codes from lack of voltage to random sensors.

 

[garywayne123]

i have an 02 spec v...guess ill just add it to the list of **** ill have to fix.lol

 

[i68k]

lol, it probably needs to be regrounded, possibly a bunch of dirt in the connector, seperating the connector. if you only use 93+ octane fuel, as youre supposed to, you should relocate your knock sensor. between this, and your p0420, you must have very horrible gas mileage.

having a first model specv, like me , you might be getting excessive knocks from a failing motor. your engine may have already ingested some ceramic into the motor, potentially causing catastrophic motor failure. if this is your case, you definately need to rebuild it, or replace the motor. i would rebuild it using the 08+ headgasket and 08+ headbolts, so its stronger than originally. hopefully, your always checking your oil and coolant levels, so it doesnt really blow up on you.

 

[garywayne123]

im ordering the header thursday, wont be able to put it on till late jan but the car willl just be sitting that whole time...i guess ill put on the header fix the sensor and runer till she quits...maybe tax time i can have her rebuilt.... cuz when it comes to enternal work like that id mess up more than id fix...what other **** should i need to look into on this car

 

[i68k]

the precat failure is a very common and bad issue, the butterfly screws should be loctited, as a screw falling into the motor while its running will ruin it completely, rendering the motor useless. other than that, just basic maintenance, tune ups, brake checks, etc. when your ses comes on, you should scan it and fix the problem relatively quickly, otherwise most ses codes cause the ecu to richen the afr and dump fuel into the exhaust, which is corrosive to the cats.

here's the faq:
http://www.b15sentra.net/forums/showthread.php?t=135241

 

[garywayne123]

well i called the dealer today because the oil is shot and its been 22 days since i had it chenged and it sat for 8 of those 22 days...plus it was 3 quarts low...so i think its toasted.he said he is going to take it to there mechanic...but im prolly fubared

 

[i68k]

...plus it was 3 quarts low...

holy tarracks stole your oil!

thats definately not a good sign. didnt you hear your timing chain grinding when you started the motor? that alone wouldve been picked up by the knock sensor. you most likely suffered from precat failure, the motor will likely need to be rebuilt or replaced. normally, by the time you get a p0420 cat code, its already too late. the ceramic from the precat probably got sucked back into the motor due to timing and lack of egr, causing excessive wear on the internals. from the sounds of it, you have fried your piston rings (very common with p0420) from ceramic and lack of oil. hopefully you still have a warranty on your motor. otherwise, you could research a rebuild with 08+ headgasket and 08+ headbolts, loctited butterflies and obviously a catless header