So my 1999 sentra se, seemed to start pulsing at low RPMs during and after i replaced a bad O2 and knock sensor.(which i believe retards the timing)

parts replaced:
plugs
wires
dist cap and rotor
fuel filter

Possible problems:
egr???


I searched but could not find much. Also I used all oem parts. Any input is helpful

it does not misfire while the engine is warming up(first few minutes), would this be a sensor issue. It is not throwing a cell but maybe there is a soft code being thrown.

Checked the timing as well and it was on 15*

Did you check the ecu for codes?

dd you gap the plugs?

the plugs were actually replaced at the end of last summer, and don't they come pre gapped? does the SR20 use an odd gap?

these are the ones i bought
http://www.autoguide.net/apf/nissan-ignition/nxitem-u8999_38075ylh_58.html


Would an autozone checker catch it even though the check engine light is not on?

Make sure the rubber "boot" on the bottom of the plug wires are seating fully on the spark plug, if they're not, you're arcing to the plug cylinder wall causing mis-fire. It's a big maybe but, it happened to me...

check ecu

lol, resurrecting this thread as I want to see what I can do for the winter car.


I actually just got the same Knock sensor and O2 codes again for "high voltage". It still misfires as it has for a while now. I have done searches and the only thing I find is that it might be a mucky egr? any ideas are helpful

thanks,

would a bad ground cause the sensors to be shorted or misfiring?

Hey check the coolant temp sensor. If those are bad, your car wont run right. Just my .02 cents

thanks, I will check it as well. I actually noticed that I have a bit of a exhaust leak at the header. It may be throwing the O2 sensor off. I bought a new gasket and will give that a shot this weekend.

chek yours fuel pump

well got it fixed for now, replaced the gasket and now there is no more misfiring.

thanks everyone