2000 Xterra Running Rough

[LanPhantom]

I bought this 2000 Xterra SE (V6 3.3) about 2 months ago with 211,000 miles on it. It was a great deal $$. A few weeks after I bought it, I put in a K&N airfilter. Then about three weeks after that it started to run rough at driving speeds and the check engine light came on. I took it to AutoZone and had them run the diag on it and it came back as the Knock Sensor. So I figured I would replace it myself. After removing all the intake manifold stuff and checking the knocks sensor to ensure it was bad (it was) we put it all back together. Once I got the engine started, it ran like a champ for about 15 minutes, then when I took it out for a test drive, it started running rought again. We check all vacuum lines and hoses and after that we decided to pull it back apart to ensure we didn't forget something under the plennum. We did find one of the fuel rail insulators had gotten munched and replaced it. We put everything back together AGAIN and it is still running rough. Durning this, I put in new Bosch Platinum plugs, new wires, cap and rotor. I check all the plugs are firing and burning well.

I'm close to taking it to the dealer, but I don't think it's too serious. Any help would be wonderful.

[OffroadX]

Yikes! How the hell did someone put 211,000 miles on a 2000 Xterra?
I'm sorry you went to the trouble and expense to replace the knock sensor, it wasn't your problem. A defective knock sensor wouldn't cause your symptoms in the first place. Unlike most auto makers, Nissan engine management systems do not use the knock sensor as a primary part of engine operation, merely as a fail-safe, and therefore it does not trigger a check-engine light if it is defective which in turn means that there is no need to replace it unless the engine is knocking for other reasons and is unable to detect it.
http://www.gatewaycleanair.com/mechanic/air6_3/dtr.htm

I'd suggest you visit the dealer and have them hook up a CONSULT unit to the OBD port and do a real-time analysis of the system data to see what's going on.

Brent

[Pbum5]

I'm close to taking it to the dealer, but I don't think it's too serious. Any help would be wonderful.[/quote]

It can be many things but
-- My 2000 X was running rough and starting hard.. I had it checked it out and it was the Fuel pres. regulator.. It had a small crack and that was enough to couse it to run like crap..

take a look at that..

[Z350_Xterra]

Originally Posted by LanPhantom

I bought this 2000 Xterra SE (V6 3.3) about 2 months ago with 211,000 miles on it. It was a great deal $$. A few weeks after I bought it, I put in a K&N airfilter. Then about three weeks after that it started to run rough at driving speeds and the check engine light came on. I took it to AutoZone and had them run the diag on it and it came back as the Knock Sensor. So I figured I would replace it myself. After removing all the intake manifold stuff and checking the knocks sensor to ensure it was bad (it was) we put it all back together. Once I got the engine started, it ran like a champ for about 15 minutes, then when I took it out for a test drive, it started running rought again. We check all vacuum lines and hoses and after that we decided to pull it back apart to ensure we didn't forget something under the plennum. We did find one of the fuel rail insulators had gotten munched and replaced it. We put everything back together AGAIN and it is still running rough. Durning this, I put in new Bosch Platinum plugs, new wires, cap and rotor. I check all the plugs are firing and burning well.

I'm close to taking it to the dealer, but I don't think it's too serious. Any help would be wonderful.

Has there been any resolution to your problem. I have a 2000 Xterra 3.3V6 having exactly the same problem! I made an appointment with my dealer but I would like to have a clue ahead of time... thanks!