Car Questions
RepairPal is your advocate for car care advice and guidance

Need help with code#4 misfire&throttle positioner switch codes and poor running

(2002 Nissan Xterra)
in Brownsville, VT on February 07, 2013
I have replaced spark plugs,wires,cap,rotor,fuel&air filters.My friend purchased vehicle last week.It had #4 misfire code & knock sensor code.I replaced knock sensor and gaskets found no cracked vac lines but she still runs poorly @idle.I added Lucas fuel treatment and dry gas with 10 gallons 93 octane.I did a cylinder compression test on 4 it was 125 lbs.Is there any problems with wiring harness or injector problems?

Displaying 2 answers & 3 comments
Popular Answer
on February 07, 2013
Engine size?? Also 125 psi aint a bunch but should fire the cylinder. Other comp. readings? Smooth out with slight throttle?
on February 07, 2013
3.3 i replaced the throttle postion switch also i didnt check comp on the other cyl it does smooth out with throttle do i need to change injector?
on February 08, 2013
Compression readings for other cylinders would be very helpful. Or at least 2 & 6. The other two, front and back, of the one you checked.
of Greg's Orange Auto on February 08, 2013
code be $4 ign or inj circuit is bad. rec your seek help from your mech as to not waste time and money
on February 08, 2013
i pulled plenum again changed injector runs great no codes thanks
RepairPal estimates are guaranteed at over 2,000 quality certified locations nationwide. Learn more

Similar Questions

View answers to similar questions from RepairPal's community of auto experts and enthusiasts.
I am on the hunt for a performance camshaft for the 3.3l supercharged motor. I also am looking for a performance chip...
how experienced are cheavy dealers with nissain xterra...mechanics should I bring it to Nissan instead? I bought it f...
Didn't find what you were looking for?