Nissan Forum banner
1 - 1 of 1 Posts

1 Posts
Discussion Starter · #1 ·
Feedback, anyone? California smog test - won't pass just the NOx level now -97 Pathfinder 6-cyl. 2WD, 155K miles:
Two years ago, had the O2 sensors replaced by my usual mechanic after it wouldn't pass (it then did). Since then, SES light is on and off sporadically for a few weeks each. OBD test here is biannual, so this time around, first try would've been an automatic fail due to light being on; went back when light was off, fail again - smog guy did tell me all the levels were really high and showed me the readouts. I took it to dealership to deal with problem directly. Had O2 sensors replaced by dealer this time; drove about 150 miles to reset computers as instructed. Went back to smog and he didn't retest, but said computers weren't reset, said to drive it more. In the next couple of days, SES came back on. Took back to dealer after 100 or so more miles; they worked it up (luckily free of charge) and got a general cylinder misfiring error message, so are telling me it could be one of "20 different things" and to drive it more before trying test again and then, if necessary, bringing back. SES was then off for a week but is now back on.

A couple of hunches I had about it may be related to fuel injection system - though this was cleaned a short time ago and reported to be good by dealer mechanic; at times will seem to sputter a bit and loss of power when accelerating (has been going on for a few months). Also, engine temp gauge usually rises to and stays at halfway mark and even a bit above during operation, though NOx is produced at an extremely high temp. Also, interestingly, when I looked thru paperwork from when I bought the truck (was a lease turn-in after 3 years) - it showed that throttle position switch had been replaced under warranty after less than a year.

Any clues/feedback? Thanks in advance.
1 - 1 of 1 Posts