Posted: Jul 08 2010 at 3:08am | IP Logged

  G'Day Frontier owners!I just got this 2001 with a 4cyl,5 spd,X-cab with 150K that was owned by a lady who lived on a dirt road.I must've spent 4-5 hours cleaning up the engine and under carriage.Of couse I had to rebuild the front end and brakes and will replace the drive shaft bearings before I start any long distance driving.The thing runs great and is in really nice shape.

  I got this thing with the check engine light on,did some basic type maintnance and the light went out.Came back on and got a code read-out from AutoZone that said "The PCM has determined that the input voltage for boost pressure sensor B is out of range for the current engine operating conditions."

  The AutoZone guy had no idea what this meant,nor do I,but being that it is a B sensor,this leads me to think there must be an A sensor,and the only dual sensors I know of are the O2 sensors,and that rear sensor had been completey incased in mud for who knows how long...what do you think about this?

  I'm John in N.Florida.Thanks

Posted: Jul 11 2010 at 10:13pm | IP Logged

I'm not even seeing a P0240 showing up for your model.

there's a P0420 that is a three way catalyst failure. 

Posted: Jul 11 2010 at 11:41pm | IP Logged

Oops!Actually my first code read at Autozone came up with the PO240 code,which specifies "boost pressure sensor "B" is out of range for the current engine operating conditions".I disconnected the battery to reset the computer and took it there again and got the PO420 code:

1) Large vacuum leak

2) Fuel system fault

3) Ignition system fault

4) Failed Bank 1 catalytic converter

  Could find no vac leak and the thing runs like a top so figured the converter/O2 sensor was a good place to start.However when I reconnected the battery I got a pretty good little spark when the terminal initially made contact with the post..My understanding is that you shouldn't get a spark like that if everything is normal..You shouldn't get any spark.Is that right or just a shade tree mechanics tale?