Lontar1

iTrader: (5)

I'm tired of the knocking.. when it was hot no knocking now that the temp is like in the 70 and even colder in the mornings. the knocking is there.

1. Have new coils
2. 93 Mobil gas
3. new spark plugs...
4. Sea foam treatment
4. BG44 vrap also.
etc etc

I have done everything there is to get rid of the knocking..... so If this knocking doesn't go away.... I going to sell the f$@@$ing car,,,,

sloppymax

iTrader: (8)

have you tried another gas station? maybe try a different brand. may want to think about borrowing or purchasing a obd2 reader and see what the timing is doing. i know its problematic in 4th gens but maybe the knock sensor went south.

SoonerFan

iTrader: (5)

i second what sloppy said

Lontar1

iTrader: (5)

I'll try that...

00Max00

I prove that no help at all. My max almost always has light knock especially obvious when cruising over 50mph when ambience air is dry, no matter what brand of gas is using, mobil, sunoco, shell etc etc. No code, no MIL. The culprit I believe is the engine is running lean. It's really annoying

VMaximus02

iTrader: (1)

Perhaps your knock sensor is at fault?

00Max00

nope. if it was the knock sensor, there would be a pending code even with no MIL. And I'm using 93 gas. 2 point higher than what nissan recommends. You don't have this problem? Try to turn off your stereo when driving, close all window and drive on a smooth road.

Puppetmaster

iTrader: (48)

No, I don't have this problem...

Hope ya get it sorted out though...

FanaticMadMax

Well I can tell you if it was the knock sensor, the car would be bucking, that won't let you accelerate anything past 25mph. Since knock sensor listen to the engine denotate making sure it's not knocking, if it does, then the sensor send that to the ECM to correct the knocking. I agree with Sloppy that you should get a OBDII done at your local autozone to get a code.

Matt_01SE_20th

iTrader: (1)

an O2 sensor might be the problem. it may not be so bad that it will trigger a code but if the sensors probes get covered in oil or carbon, they will be off. this might be leaning out you A/F mixture. i might be wrong though, you would have to backprobe to find out for sure.

sloppymax

iTrader: (8)

lots of 4th gens have had issues with knock sensors and it definately hurts accleration but it will certainly go past 25mph.

GBAUER

iTrader: (2)

I've had the same problem since about 85k (up to about 96k now). No CEL. Good, high octane gas, did the Seafoam. ect. ect. No autozones in MD that I've found (I miss them from IN!) and besides, the CEL light isn't on anyway. any options to test the 02 sensor? how? If not that, then what else to check?

00Max00

most time if a o2 sensor failed the a/f mixture would be richer not lean cause the ecu cannot get any information from the sensor then looks up a fixed table for the default setting, usually the default setting is richer than normal to ensure drivability. correct me if i wrong.

Matt_01SE_20th

iTrader: (1)

due to the fact that the MIL is not on the fuel map has not reset to default. the thing is that the O2 sensor could be measuring wrong, and giving a low voltage indicating lean, this usually happens when the sensor is functioning properly but it cannot get an accurate reading due to a foriegn material coating the sensor probe. the MIL is not on because the O2 sensor voltage is still within acceptable ranges, and the respose is still fast enough to not trip the MIL. this is a rare case but i have heard of it before and since it seems only a few people are experiencing this i figured i would put this possibility out there.

Lontar1

iTrader: (5)

I pulled the code and it is the famous P0420, which I think I have an O2 sensor bad.

IceY2K1

iTrader: (3)

MAF or intake air leak......IMHO.

Lontar1

iTrader: (5)

How can I test for that???

sloppymax

iTrader: (8)

its not the o2. to cure it, you will need nissan to flash the ecu as per the TSB listed there. if that does not fix it then the main cat may need to be replaced. keep in mind this is covered 8yr/80k miles. if the pinging persists after that and switching gas stations then i would take ice's advice and check out the maf. you can pick up a haynes manual at any parts store and it outlines how to test.