[jhphoto21]

I have a 2003 X with the 3.3-SC engine that now has a little over 251k miles on it. Had the truck since it was brand new and plan to keep it.

Lately, I've been battling some issues like oil leaks, etc. I just had the rear main and crankshaft seals replaced to stop oil leaks and did the valve cover gaskets about 6 months ago (with plugs, all lifters and two bad rockers). Other than burning oil...this should be solved.

I'm getting some very choppy running and idle right now and even an occasional flashing SEL when the issue gets bad driving down the highway.

I've checked the codes with my reader and found the following 5 stored codes:

1. 0304 - Cylinder 4 misfire
2. 0328 - Knock Sensor / Circuit B1
3. 0304 - Cylinder 4 misfire
4. 0430 - Catalyst System Bank 2
5. 0328 - Knock Sensor / Circuit B1

From what I've been able to find in these forums, it could be a distributor issue (never replaced) that is causing the misfire and that is likely setting off the knock sensor. Does that sound about right? Is there a way to diagnose this a little better or any other suggestions based on the whole collection of codes?

Also, anyone have experience with the 0430 code?

Thanks much guys for any feedback.

 

[Ben Pedersen]

Have you checked your distributor cap, rotor, and #4 plug wire? I know you said you changed the plugs, so I assume that that isn't the issue.

 

[jhphoto21]

I did check the #4 plug (which is only 7 months old now) and the wire (about 2 years old), but no issues. I also replaced the distributor yesterday (distributor, cap and rotor with new), but it did not solve the problem. I'm still hoping that I can get it sorted out though.

Thanks for the ideas Ben!

 

[Ben Pedersen]

Apologies for not being much help. I'm not the world's greatest mechanic, but sometimes the simple things are all it takes!

 

[jhphoto21]

I'm right there with you. That's why I replaced the distributor.

UPDATE: I took the vehicle in for a compression test and the results are about what I expected...major compression problems that you would see with little power from the engine. It could mean a reman engine, so keep your fingers crossed for me that I can avoid that expense. Like I noted before...I'm keeping the Xterra, so I'll definitely do that if need be.

 

[netdobeiras]

If you are getting a choppy idle check your fresh air intake tube. the one right in front of the throttle body. sometimes it has holes underneath it. i have been thinking of replacing mine since it has a few tears but no noticeable holes.